Cherry-pick of `mesa: remove GL_UNSIGNED_BYTE as supported for snorm reads`
What does this MR do and why?
mesa: remove GL_UNSIGNED_BYTE as supported for snorm reads
UNSIGNED_BYTE should not be allowed for reading snorm color buffers.
Signed-off-by: Tapani Pälli tapani.palli@intel.com Reviewed-by: Marek Olšák marek.olsak@amd.com