Multi-platform DWIN_CREALITY_LCD support (#20738)

Co-authored-by: Scott Lahteine <thinkyhead@users.noreply.github.com>

Marlin/src/HAL/STM32F1/HAL.h

@@ -109,8 +109,9 @@
   #else
     #error "LCD_SERIAL_PORT must be -1 or from 1 to 3. Please update your configuration."
   #endif
-
-  #define SERIAL_GET_TX_BUFFER_FREE() LCD_SERIAL.availableForWrite()
+  #if HAS_DGUS_LCD
+    #define SERIAL_GET_TX_BUFFER_FREE() LCD_SERIAL.availableForWrite()
+  #endif
 #endif
 
 // Set interrupt grouping for this MCU