i965: Massage argument list of brw_emit_surface_state().

i965: Massage argument list of brw_emit_surface_state().

This commit does three different things in a single pass in order to
keep the amount of churn low: Remove the for_gather boolean argument
which was unused, pass the isl_view argument by value rather than by
reference since I'll have to modify it from within the function, and
add a target argument to allow callers to bind textures using a target
other than the original.  The prototype of the function now looks
like:

 void brw_emit_surface_state(struct brw_context *brw,
                             struct intel_mipmap_tree *mt,
                             GLenum target, struct isl_view view,
                             uint32_t mocs, uint32_t *surf_offset, int surf_index,
                             unsigned read_domains, unsigned write_domains);

Reviewed-by: Kenneth Graunke <kenneth@whitecape.org>