lcd: JZ4750D: Unify jz4740_lcd_*.h
lcd: JZ4750D: Some more cleanups for jz4750_lcd_a380.c and jz4750_lcd_rzx50.c
lcd: JZ4750D: Use jz4750_lcd.h include for a380 and rzx50 boards
lcd: JZ4750D: Remove unused headers