drivers/aspeed/common: Add support for high resolution framebuffer

* Implement reading EDID over software I2C.
* Fall back to VGA if no monitor connected for BMC KVM
* Copy the linux kernel code and add a bunch of wrapper structs to make it
  compile.
* Convert the EDID to a drm_display_mode, which is understood by the
  driver.
* Properly select HAVE_LINEAR_FRAMEBUFFER and HAVE_VGA_TEXT_FRAMEBUFFER

Tested on Supermicro X11SSH-TF using FullHD VGA monitor.
Initializes the graphics in about 1 second, which is twice as fast as the
VGA Option ROM.

The framebuffer is advertised and working in tianocore.

Change-Id: I7803566b64158405efc04a39f80a0ec98b44e646
Signed-off-by: Patrick Rudolph <patrick.rudolph@9elements.com>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/35726
Reviewed-by: Philipp Deppenwiese <zaolin.daisuki@gmail.com>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>

0 files changed, 0 insertions, 0 deletions