mesa: Ignore SRGB when determining compatible resolve formats.

mesa: Ignore SRGB when determining compatible resolve formats.

MSAA resolves and other blit-like operations ignore SRGB state anyway,
so we should be able to safely allow resolves between compatible
SRGB/linear formats like SRGBA8 and RGBA8888.

This matches the behavior of the nVidia and AMD binary drivers.

Fixes completely black rendering when using multisampling in L4D2.

NOTE: This is a candidate for the 9.0 branch.

Reviewed-by: Paul Berry <stereotype441@gmail.com>
Signed-off-by: Kenneth Graunke <kenneth@whitecape.org>
(cherry picked from commit c96828ecb46b5aee3121a018be365b738c35cbdc)