Fix SKR 1.4 LCD / ADC Keypad sanity-check (MarlinFirmware#18670)

Author: ellensp

Marlin/src/pins/lpc1768/pins_BTT_SKR_V1_3.h

@@ -261,6 +261,10 @@
     #define LCD_PINS_ENABLE         EXPA1_03_PIN
     #define LCD_PINS_D4             EXPA1_05_PIN
 
+  #elif HAS_ADC_BUTTONS
+
+    #error "ADC BUTTONS do not work unmodifed on SKR 1.3, The ADC ports cannot take more than 3.3v."
+
   #else                                           // !CR10_STOCKDISPLAY
 
     #define LCD_PINS_RS             EXPA1_07_PIN

Marlin/src/pins/lpc1768/pins_BTT_SKR_V1_4.h

@@ -250,7 +250,7 @@
     #define LCD_PINS_ENABLE                P1_23
     #define LCD_PINS_D4                    P1_21
 
-  #elif HAS_GRAPHICAL_LCD
+  #else
 
     #define BTN_ENC                        P0_28  // (58) open-drain
     #define LCD_PINS_RS                    P1_19
@@ -312,14 +312,14 @@
 
     #endif // !FYSETC_MINI_12864
 
-  #elif HAS_CHARACTER_LCD
-
-    #error "Character LCD not yet supported for SKR 1.4."
-
-  #endif
+  #endif // HAS_GRAPHICAL_LCD
 
 #endif // HAS_SPI_LCD
 
+#if HAS_ADC_BUTTONS
+  #error "ADC BUTTONS do not work unmodifed on SKR 1.4, The ADC ports cannot take more than 3.3v."
+#endif
+
 //
 // Neopixel LED
 //