[2.0.x] Fix compile errors (#9141)

* Update persistent_store_impl.cpp
* Remove define BYTE from serial functions since Arduino docs typically show 0 for the normal case.

Marlin/src/HAL/HAL_AVR/MarlinSerial.h

@@ -75,7 +75,6 @@
 #define HEX 16
 #define OCT 8
 #define BIN 2
-#define BYTE 0
 
 #ifndef USBCON
   // We're using a ring buffer (I think), in which rx_buffer_head is the index of the
@@ -126,8 +125,8 @@
       FORCE_INLINE static void print(const String& s) { for (int i = 0; i < (int)s.length(); i++) write(s[i]); }
       FORCE_INLINE static void print(const char* str) { write(str); }
 
-      static void print(char, int = BYTE);
-      static void print(unsigned char, int = BYTE);
+      static void print(char, int = 0);
+      static void print(unsigned char, int = 0);
       static void print(int, int = DEC);
       static void print(unsigned int, int = DEC);
       static void print(long, int = DEC);
@@ -136,8 +135,8 @@
 
       static void println(const String& s);
       static void println(const char[]);
-      static void println(char, int = BYTE);
-      static void println(unsigned char, int = BYTE);
+      static void println(char, int = 0);
+      static void println(unsigned char, int = 0);
       static void println(int, int = DEC);
       static void println(unsigned int, int = DEC);
       static void println(long, int = DEC);

Marlin/src/HAL/HAL_DUE/MarlinSerialUSB_Due.h

@@ -38,7 +38,6 @@
 #define HEX 16
 #define OCT 8
 #define BIN 2
-#define BYTE 0
 
 class MarlinSerialUSB {
 
@@ -65,8 +64,8 @@ public:
   static FORCE_INLINE void print(const String& s) { for (int i = 0; i < (int)s.length(); i++) write(s[i]); }
   static FORCE_INLINE void print(const char* str) { write(str); }
 
-  static void print(char, int = BYTE);
-  static void print(unsigned char, int = BYTE);
+  static void print(char, int = 0);
+  static void print(unsigned char, int = 0);
   static void print(int, int = DEC);
   static void print(unsigned int, int = DEC);
   static void print(long, int = DEC);
@@ -75,8 +74,8 @@ public:
 
   static void println(const String& s);
   static void println(const char[]);
-  static void println(char, int = BYTE);
-  static void println(unsigned char, int = BYTE);
+  static void println(char, int = 0);
+  static void println(unsigned char, int = 0);
   static void println(int, int = DEC);
   static void println(unsigned int, int = DEC);
   static void println(long, int = DEC);

Marlin/src/HAL/HAL_DUE/MarlinSerial_Due.h

@@ -39,7 +39,6 @@
 #define HEX 16
 #define OCT 8
 #define BIN 2
-#define BYTE 0
 
 // Define constants and variables for buffering incoming serial data.  We're
 // using a ring buffer (I think), in which rx_buffer_head is the index of the
@@ -106,8 +105,8 @@ public:
   FORCE_INLINE static void print(const String& s) { for (int i = 0; i < (int)s.length(); i++) write(s[i]); }
   FORCE_INLINE static void print(const char* str) { write(str); }
 
-  static void print(char, int = BYTE);
-  static void print(unsigned char, int = BYTE);
+  static void print(char, int = 0);
+  static void print(unsigned char, int = 0);
   static void print(int, int = DEC);
   static void print(unsigned int, int = DEC);
   static void print(long, int = DEC);
@@ -116,8 +115,8 @@ public:
 
   static void println(const String& s);
   static void println(const char[]);
-  static void println(char, int = BYTE);
-  static void println(unsigned char, int = BYTE);
+  static void println(char, int = 0);
+  static void println(unsigned char, int = 0);
   static void println(int, int = DEC);
   static void println(unsigned int, int = DEC);
   static void println(long, int = DEC);

Marlin/src/HAL/HAL_LPC1768/HardwareSerial.h

@@ -77,8 +77,6 @@ public:
   #define HEX 16
   #define OCT 8
   #define BIN 2
-  #define BYTE 0
-
 
   void print_bin(uint32_t value, uint8_t num_digits) {
     uint32_t mask = 1 << (num_digits -1);

Marlin/src/HAL/HAL_LPC1768/serial.h

@@ -129,7 +129,6 @@ public:
   #define HEX 16
   #define OCT 8
   #define BIN 2
-  #define BYTE 0
 
   void print_bin(uint32_t value, uint8_t num_digits) {
     uint32_t mask = 1 << (num_digits -1);

Marlin/src/module/configuration_store.h

@@ -116,7 +116,7 @@ class MarlinSettings {
       );
       static bool size_error(const uint16_t size
         #if ADD_PORT_ARG
-          const int8_t port=-1
+          , const int8_t port=-1
         #endif
       );
     #endif