freedreno/a6xx: remove special handling based on MRT format

Logicop in particular is supposed to work for integer formats.. but
maybe this situation doesn't happen in gles.  The only thing that isn't
required for integer formats is blending.

Signed-off-by: Rob Clark <robdclark@chromium.org>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/merge_requests/3565>
1 file changed