A list of current display drivers:
AlteraFramereader - Support for the "Altera Frame Reader IP Core"
ED060SC4 - E-Ink display
framebuffer - Supports any non-palletized, non-bitpacked color display with a framebuffer
Fb24bpp - Same as 'framebuffer' driver but supports RGB888 and BGR888 packed framebuffer formats.
HX8347D - Mid-sized color LCD displays eg RGB565 320x240
ILI9320 - Mid-sized color LCD displays eg RGB565 320x240
ILI9325 - Mid-sized color LCD displays eg RGB565 320x240
ILI9341 - Mid-sized color LCD displays eg RGB565 320x240
ILI9342 - Mid-sized color LCD displays eg RGB565 320x240
ILI93xx - Mid-sized color LCD displays eg RGB565 320x240 (attempt at a common driver)
ILI9481 - Mid-sized color LCD displays eg RGB565 320x240
KS0108 - Small monochrome LCD
LGDP4532 - Mid-sized color LCD displays eg RGB565 320x240
Nokia6610GE8 - Small (130x130) 12bit color LCD
Nokia6610GE12 - Small (130x130) 12bit color LCD (untested)
PCD8544 - Small monochrome LCD
PCF8812 - Small monochrome LCD
R61505U - Mid-sized color LCD displays eg RGB565 320x240
RA6963 - Small monochrome LCD
RA8875 - Mid-sized color LCD displays eg RGB565 320x240
S6D1121 - Mid-sized color LCD displays eg RGB565 320x240
SPFD54124B - Mid-sized color LCD displays eg RGB565 320x240
SSD1289 - Mid-sized color LCD displays eg RGB565 320x240
SSD1306 - Small monochrome LCD
SSD1322 - Small 16 level grayscale LCD
SSD1331 - Small hardware accelerated OLED display RGB565 96x64
SSD1351 - Mid-sized color LCD displays eg RGB565 320x240
SSD1848 - Small grayscale LCD eg 2-Bit 130x130
SSD1963 - Mid-sized color LCD displays eg RGB565 320x240
SSD2119 - Mid-sized color LCD displays eg RGB565 320x240
ST7565 - Small monochrome LCD
STM32LTDC - STM32 ART graphics STM32F4 and STM32F7 series CPU's
TestStub - NULL driver just to test compile
TLS8204 - Small monochrome LCD
UC8173 - E-Ink display driver
UC1601s - Small (64x132) monochrome LCD
UC1610 - Small (78x64 or 160x104) 4 level grayscale LCD
UC8175 - Small E-Ink display
WS29EPD - Small E-Ink display by WaveShare
QImage - Driver that allows rendering into a QImage object (of the Qt framework)
uGFXnet - Remote Network display (in drivers/multiple/uGFXnet directory)
Win32 - Microsoft Windows (in drivers/multiple/Win32 directory)
X - X Windows (Xlib) (in drivers/multiple/X directory)