drm: atmel-hlcdc: add LCD controller layer definition for sam9x75

Add the LCD controller layer definition and descriptor structure for
sam9x75 for the following layers:
- Base Layer
- Overlay1 Layer
- Overlay2 Layer
- High End Overlay

Signed-off-by: Manikandan Muralidharan <manikandan.m@microchip.com>
Acked-by: Sam Ravnborg <sam@ravnborg.org>
Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20240424053351.589830-9-manikandan.m@microchip.com