There is no requirement for VBE modes to be listed in increasing order
of resolution. With the present logic, this can cause e.g. a 1024x768
mode to be selected if the user asks for 640x480, if the 1024x768 mode
is earlier in the mode list.
Define a scoring system for modes as
score = ( width * height - bpp )
and choose the mode with the lowest score among all acceptable modes.
This should prefer to choose the mode closest to the requested
resolution, with a slight preference for higher colour depths.
Reported-by: Robin Smidsrød <robin@smidsrod.no>
Signed-off-by: Michael Brown <mcb30@ipxe.org>