Arduino_GFX Add more support for display drivers!

This fork is Arduino_ The fork of GFX-1.3.7 has been added to this fork for the following display drivers：

Screen type	Driver chip	communication protocol
AMOLED	SH8601	QSPI

Add the following functions

Function	Effects
void Display_Brightness(uint8_t brightness)	Adjusting display brightness
void SetContrast(uint8_t Contrast)	Adjusting Display Contrast(Sunlight Readability Enhancement)