i965/surface_state: Drop brw_aux_surface_disabled

i965/surface_state: Drop brw_aux_surface_disabled

The only purpose of this function is to disable aux on texture surfaces
when the corresponding renderbuffer has aux disabled.  However, the act
of disabling aux on the renderbuffer will cause it to be resolved and
intel_miptree_texture_aux_usage will already check the resolved status
of a texture and return ISL_AUX_USAGE_NONE for it.  Even if we used CCS
for it, that wouldn't really be a problem because the CCS will be in the
pass-through state and so it would effectively be ignored.

Cc: mesa-stable@lists.freedesktop.org
Reviewed-by: Kenneth Graunke <kenneth@whitecape.org>