Init servo pins in HAL_init (#14425)

Marlin/src/HAL/HAL_STM32F1/HAL.h

@@ -117,9 +117,8 @@
   #define NUM_SERIAL 1
 #endif
 
-// Use HAL_init() to set interrupt grouping.
-#define HAL_INIT
-void HAL_init();
+// Set interrupt grouping for this MCU
+void HAL_init(void);
 
 /**
  * TODO: review this to return 1 for pins that are not analog input