This is separate to the VESA driver, as the VESA driver requires
using the VBE BIOS. Under UEFI, we don't have the VBE BIOS, nor
are we able to switch modes after leaving UEFI Boot Services, so
a dumb framebuffer driver seemed like the easier way to approach
the problem.
The framebuffer & vesa drivers now test for the presence of the
VESA_MODES_BOOT_INFO boot item to distinguish between which driver
to use. Also added check for the VESA mode count to determine
whether to add the VESA_MODES_BOOT_INFO item.
UEFI video updated to explicitly zero out the VESA and EDID
boot data.
48494219eb