Clean up LCD width/height determination

Marlin/src/config/examples/Geeetech/GT2560/Configuration.h

@@ -2036,7 +2036,7 @@
 #if ENABLED(ULTIMAKERCONTROLLER) || ENABLED(REPRAP_DISCOUNT_SMART_CONTROLLER) || ENABLED(G3D_PANEL) || ENABLED(MKS_MINI_12864)
   #define SDSUPPORT   // Force SD Card support on for these displays
 #elif DISABLED(LIGHTWEIGHT_UI)
-  #define LCD_WIDTH_OVERRIDE 20 // Default is 22. For this Geeetech use 20.
+  #define LCD_WIDTH 20 // Default is 22. For this Geeetech use 20.
 #endif
 
 // Allow servo angle to be edited and saved to EEPROM

Marlin/src/inc/Conditionals_post.h

@@ -1630,37 +1630,25 @@
 #endif
 
 // Get LCD character width/height, which may be overridden by pins, configs, etc.
-#if HAS_GRAPHICAL_LCD
 #ifndef LCD_WIDTH
-    #ifdef LCD_WIDTH_OVERRIDE
-      #define LCD_WIDTH LCD_WIDTH_OVERRIDE
-    #elif ENABLED(LIGHTWEIGHT_UI)
+  #if ENABLED(LIGHTWEIGHT_UI)
     #define LCD_WIDTH 16
-    #else
+  #elif HAS_GRAPHICAL_LCD
     #define LCD_WIDTH 22
+  #elif ENABLED(ULTIPANEL)
+    #define LCD_WIDTH 20
+  #elif HAS_SPI_LCD
+    #define LCD_WIDTH 16
   #endif
 #endif
 #ifndef LCD_HEIGHT
-    #ifdef LCD_HEIGHT_OVERRIDE
-      #define LCD_HEIGHT LCD_HEIGHT_OVERRIDE
-    #elif ENABLED(LIGHTWEIGHT_UI)
+  #if ENABLED(LIGHTWEIGHT_UI)
     #define LCD_HEIGHT 4
-    #else
+  #elif HAS_GRAPHICAL_LCD
     #define LCD_HEIGHT 5
-    #endif
-  #endif
   #elif ENABLED(ULTIPANEL)
-  #ifndef LCD_WIDTH
-    #define LCD_WIDTH 20
-  #endif
-  #ifndef LCD_HEIGHT
     #define LCD_HEIGHT 4
-  #endif
   #elif HAS_SPI_LCD
-  #ifndef LCD_WIDTH
-    #define LCD_WIDTH 16
-  #endif
-  #ifndef LCD_HEIGHT
     #define LCD_HEIGHT 2
   #endif
 #endif