Fix: Contrast override in pins files

Move contrast handling to `Conditionals_post.h` so pins files can override the LCD defaults.

Marlin/src/inc/Conditionals_LCD.h

 
   #define DOGLCD
   #define IS_ULTIPANEL
-  #define LCD_CONTRAST_MIN  60
-  #define LCD_CONTRAST_MAX 140
-  #define LCD_CONTRAST_INIT 90
 
 #elif ENABLED(ZONESTAR_LCD)
 
   #define IS_ULTIPANEL
 
   #if ENABLED(miniVIKI)
-    #define LCD_CONTRAST_MIN      75
-    #define LCD_CONTRAST_MAX     115
-    #define LCD_CONTRAST_INIT     95
     #define U8GLIB_ST7565_64128N
   #elif ENABLED(VIKI2)
-    #define LCD_CONTRAST_MIN       0
-    #define LCD_CONTRAST_MAX     255
-    #define LCD_CONTRAST_INIT    140
     #define U8GLIB_ST7565_64128N
   #elif ENABLED(ELB_FULL_GRAPHIC_CONTROLLER)
-    #define LCD_CONTRAST_MIN      90
-    #define LCD_CONTRAST_MAX     130
-    #define LCD_CONTRAST_INIT    110
     #define U8GLIB_LM6059_AF
     #define SD_DETECT_INVERTED
   #elif ENABLED(AZSMZ_12864)
-    #define LCD_CONTRAST_MIN     120
-    #define LCD_CONTRAST_MAX     255
-    #define LCD_CONTRAST_INIT    190
     #define U8GLIB_ST7565_64128N
   #endif
 
 #elif ENABLED(MKS_MINI_12864)
 
   #define MINIPANEL
-  #define LCD_CONTRAST_MAX  255
-  #define LCD_CONTRAST_INIT 150
 
 #elif ANY(FYSETC_MINI_12864_X_X, FYSETC_MINI_12864_1_2, FYSETC_MINI_12864_2_0, FYSETC_MINI_12864_2_1)
 
   #define FYSETC_MINI_12864
   #define DOGLCD
   #define IS_ULTIPANEL
-  #define LCD_CONTRAST_MIN    0
-  #define LCD_CONTRAST_MAX  255
-  #define LCD_CONTRAST_INIT 220
   #define LED_COLORS_REDUCE_GREEN
   #if HAS_POWER_SWITCH && EITHER(FYSETC_MINI_12864_2_0, FYSETC_MINI_12864_2_1)
     #define LED_BACKLIGHT_TIMEOUT 10000
   #define IS_ULTIPANEL
   #define U8GLIB_SSD1309
   #define LCD_RESET_PIN LCD_PINS_D6 //  This controller need a reset pin
-  #define LCD_CONTRAST_MIN    0
-  #define LCD_CONTRAST_MAX  254
-  #define LCD_CONTRAST_INIT 127
   #define ENCODER_PULSES_PER_STEP 2
   #define ENCODER_STEPS_PER_MENU_ITEM 2
 
   #if ENABLED(MAKRPANEL)
     #define U8GLIB_ST7565_64128N
   #endif
-  #ifndef LCD_CONTRAST_INIT
-    #define LCD_CONTRAST_INIT    17
-  #endif
 #endif
 
 #if ENABLED(IS_U8GLIB_SSD1306)

Marlin/src/inc/Conditionals_post.h

 #endif
 
 /**
- * Default LCD contrast for Graphical LCD displays
+ * LCD Contrast for Graphical Displays
  */
-#define HAS_LCD_CONTRAST defined(LCD_CONTRAST_INIT)
+#if ENABLED(CARTESIO_UI)
+  #define _LCD_CONTRAST_MIN   60
+  #define _LCD_CONTRAST_INIT  90
+  #define _LCD_CONTRAST_MAX  140
+#elif ENABLED(miniVIKI)
+  #define _LCD_CONTRAST_MIN   75
+  #define _LCD_CONTRAST_INIT  95
+  #define _LCD_CONTRAST_MAX  115
+#elif ENABLED(VIKI2)
+  #define _LCD_CONTRAST_INIT 140
+#elif ENABLED(ELB_FULL_GRAPHIC_CONTROLLER)
+  #define _LCD_CONTRAST_MIN   90
+  #define _LCD_CONTRAST_INIT 110
+  #define _LCD_CONTRAST_MAX  130
+#elif ENABLED(AZSMZ_12864)
+  #define _LCD_CONTRAST_MIN  120
+  #define _LCD_CONTRAST_INIT 190
+#elif ENABLED(MKS_MINI_12864)
+  #define _LCD_CONTRAST_INIT 150
+#elif ANY(FYSETC_MINI_12864_X_X, FYSETC_MINI_12864_1_2, FYSETC_MINI_12864_2_0, FYSETC_MINI_12864_2_1)
+  #define _LCD_CONTRAST_INIT 220
+#elif ENABLED(ULTI_CONTROLLER)
+  #define _LCD_CONTRAST_INIT 127
+  #define _LCD_CONTRAST_MAX  254
+#elif EITHER(MAKRPANEL, MINIPANEL)
+  #define _LCD_CONTRAST_INIT  17
+#endif
+
+#define HAS_LCD_CONTRAST defined(_LCD_CONTRAST_INIT)
 #if HAS_LCD_CONTRAST
-  #ifndef DEFAULT_LCD_CONTRAST
-    #define DEFAULT_LCD_CONTRAST LCD_CONTRAST_INIT
-  #endif
   #ifndef LCD_CONTRAST_MIN
-    #define LCD_CONTRAST_MIN 0
+    #ifdef _LCD_CONTRAST_MIN
+      #define LCD_CONTRAST_MIN _LCD_CONTRAST_MIN
+    #else
+      #define LCD_CONTRAST_MIN 0
+    #endif
+  #endif
+  #ifndef LCD_CONTRAST_INIT
+    #define LCD_CONTRAST_INIT _LCD_CONTRAST_INIT
   #endif
   #ifndef LCD_CONTRAST_MAX
-    #define LCD_CONTRAST_MAX MAX(63, LCD_CONTRAST_INIT)
+    #ifdef _LCD_CONTRAST_MAX
+      #define LCD_CONTRAST_MAX _LCD_CONTRAST_MAX
+    #else
+      #define LCD_CONTRAST_MAX 63
+    #endif
+  #endif
+  #ifndef DEFAULT_LCD_CONTRAST
+    #define DEFAULT_LCD_CONTRAST LCD_CONTRAST_INIT
   #endif
 #endif