Introduces a very basic frame buffer driver implementation for the RPi4B
which is registered at startup and works with frame buffer graphics
examples (and LVGL). Graphics are displayed on the HDMI0 and HDMI1
output, depending which one is plugged into the display. I have not
tested using both at once, nor does the driver account for that. They
are both referred to as display 0, plane 0 since the RPi4B frame buffer
interface does not seem to have a way of distinguishing.
Signed-off-by: Matteo Golin <matteo.golin@gmail.com>
310a808d3d