Reduce STM32_F4_F7 pin warnings

Marlin/src/HAL/HAL_STM32_F4_F7/fastio_STM32_F4_F7.h

@@ -27,8 +27,6 @@
  * These use GPIO functions instead of Direct Port Manipulation, as on AVR.
  */
 
-#define _BV(b) (1 << (b))
-
 #define READ(IO)                digitalRead(IO)
 #define WRITE(IO,V)             digitalWrite(IO,V)
 
@@ -66,6 +64,7 @@
 
 #define _STM32_PIN(P,PN) ((PORT##P * 16) + PN)
 
+#ifndef PA0
   #define PA0  _STM32_PIN(A,  0)
   #define PA1  _STM32_PIN(A,  1)
   #define PA2  _STM32_PIN(A,  2)
@@ -82,7 +81,9 @@
   #define PA13 _STM32_PIN(A, 13)
   #define PA14 _STM32_PIN(A, 14)
   #define PA15 _STM32_PIN(A, 15)
+#endif
 
+#ifndef PB0
   #define PB0  _STM32_PIN(B,  0)
   #define PB1  _STM32_PIN(B,  1)
   #define PB2  _STM32_PIN(B,  2)
@@ -99,7 +100,9 @@
   #define PB13 _STM32_PIN(B, 13)
   #define PB14 _STM32_PIN(B, 14)
   #define PB15 _STM32_PIN(B, 15)
+#endif
 
+#ifndef PC0
   #define PC0  _STM32_PIN(C,  0)
   #define PC1  _STM32_PIN(C,  1)
   #define PC2  _STM32_PIN(C,  2)
@@ -116,7 +119,9 @@
   #define PC13 _STM32_PIN(C, 13)
   #define PC14 _STM32_PIN(C, 14)
   #define PC15 _STM32_PIN(C, 15)
+#endif
 
+#ifndef PD0
   #define PD0  _STM32_PIN(D,  0)
   #define PD1  _STM32_PIN(D,  1)
   #define PD2  _STM32_PIN(D,  2)
@@ -133,7 +138,9 @@
   #define PD13 _STM32_PIN(D, 13)
   #define PD14 _STM32_PIN(D, 14)
   #define PD15 _STM32_PIN(D, 15)
+#endif
 
+#ifndef PE0
   #define PE0  _STM32_PIN(E,  0)
   #define PE1  _STM32_PIN(E,  1)
   #define PE2  _STM32_PIN(E,  2)
@@ -150,11 +157,12 @@
   #define PE13 _STM32_PIN(E, 13)
   #define PE14 _STM32_PIN(E, 14)
   #define PE15 _STM32_PIN(E, 15)
+#endif
 
 #ifdef STM32F7
-  #define PORTF 5
-  #define PORTG 6
 
+  #ifndef PF0
+    #define PORTF 5
     #define PF0  _STM32_PIN(F,  0)
     #define PF1  _STM32_PIN(F,  1)
     #define PF2  _STM32_PIN(F,  2)
@@ -171,7 +179,10 @@
     #define PF13 _STM32_PIN(F, 13)
     #define PF14 _STM32_PIN(F, 14)
     #define PF15 _STM32_PIN(F, 15)
+  #endif
 
+  #ifndef PG0
+    #define PORTG 6
     #define PG0  _STM32_PIN(G,  0)
     #define PG1  _STM32_PIN(G,  1)
     #define PG2  _STM32_PIN(G,  2)
@@ -188,5 +199,6 @@
     #define PG13 _STM32_PIN(G, 13)
     #define PG14 _STM32_PIN(G, 14)
     #define PG15 _STM32_PIN(G, 15)
+  #endif
 
 #endif // STM32GENERIC && STM32F7