i965: Add #defines for Memory Object Control State fields on Gen7-7.5.

i965: Add #defines for Memory Object Control State fields on Gen7-7.5.

The L3 controls are identical on all platforms, but LLC differs:
- Ivybridge has a "cache in LLC" flag
- Baytrail has no LLC, but instead has a snoop bit:
  "data accesses in this page must be snooped in the CPU caches."
- Haswell has writeback/uncached flags for LLC and eLLC (eDRAM).

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