st/mesa: use R10G10B10X2 format where applicable

This is the last step of fixing
dEQP-GLES3.functional.fbo.completeness.renderable.texture.color0.rgb_unsigned_int_2_10_10_10_rev
for radeonsi.

Reviewed-by: Marek Olšák <marek.olsak@amd.com>
1 file changed