i965: Replace intel_state.c enums with those from brw_defines.h.

i965: Replace intel_state.c enums with those from brw_defines.h.

Both intel_context.h and brw_defines.h have #defines for comparison
functions, stencil ops, blending logic ops, and blending factors.
They're exactly the same values, so it makes sense to pick one.

brw_defines.h is the logical place for this kind of stuff, so this patch
converts intel_state.c to use the set defined there.

Signed-off-by: Kenneth Graunke <kenneth@whitecape.org>
Reviewed-by: Chad Versace <chad.versace@linux.intel.com>