🩹 Fix SainSmart LCD (#24672)

Marlin/src/inc/Conditionals_LCD.h

@@ -373,6 +373,7 @@
 
   #define LCD_I2C_TYPE_PCF8575    // I2C Character-based 12864 display
   #define LCD_I2C_ADDRESS 0x27    // I2C Address of the port expander
+  #define IS_ULTIPANEL 1
 
   #if ENABLED(LCD_SAINSMART_I2C_2004)
     #define LCD_WIDTH 20