Fix duplicate board IDs (#14310)

Marlin/Makefile

@@ -273,7 +273,7 @@ else ifeq ($(HARDWARE_MOTHERBOARD),304)
 # Einsy Retro
 else ifeq ($(HARDWARE_MOTHERBOARD),305)
 # Elefu Ra Board (v3)
-else ifeq ($(HARDWARE_MOTHERBOARD),21)
+else ifeq ($(HARDWARE_MOTHERBOARD),23)
 # Leapfrog
 else ifeq ($(HARDWARE_MOTHERBOARD),999)
 # Mega controller

Marlin/src/core/boards.h

@@ -112,7 +112,7 @@
 #define BOARD_MINIRAMBO_10A     303   // Mini-Rambo 1.0a
 #define BOARD_EINSY_RAMBO       304   // Einsy Rambo
 #define BOARD_EINSY_RETRO       305   // Einsy Retro
-#define BOARD_ELEFU_3           21    // Elefu Ra Board (v3)
+#define BOARD_ELEFU_3           23    // Elefu Ra Board (v3)
 #define BOARD_LEAPFROG          999   // Leapfrog
 #define BOARD_MEGACONTROLLER    310   // Mega controller
 #define BOARD_SCOOVO_X9H        321   // abee Scoovo X9H
@@ -247,7 +247,7 @@
 #define BOARD_MORPHEUS         1806   // STM32F103C8/STM32F103CB Libmaple based stm32f1 controller
 #define BOARD_MKS_ROBIN        1808   // MKS Robin / STM32F103ZET6
 #define BOARD_BIGTREE_SKR_MINI_V1_1 1814 // STM32F103RC
-#define BOARD_JGAURORA_A5S_A1  1810   // JGAurora A5S A1 / STM32F103ZET6
+#define BOARD_JGAURORA_A5S_A1  1820   // JGAurora A5S A1 / STM32F103ZET6
 
 //
 // STM32 ARM Cortex-M4F