This allows eglCreateImage() to accept textures of said format.
Patch 1/2 to fix
dEQP-EGL.functional.image.modify.tex_rgb5_a1_tex_subimage_rgba8
on Intel.
Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=99185
Cc: Haixia Shi <hshi@chromium.org>
Reviewed-by: Tapani Pälli <tapani.palli@intel.com>
Cc: "13.0" <mesa-stable@lists.freedesktop.org>