drm/i915/selftests: Add coverage of mocs registers

Probe the mocs registers for new contexts and across GPU resets. Similar
to intel_workarounds, we have tables of what register values we expect
to see, so verify that user contexts are affected by them. In the
future, we should add tests similar to intel_sseu to cover dynamic
reconfigurations.

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Prathap Kumar Valsan <prathap.kumar.valsan@intel.com>
Cc: Mika Kuoppala <mika.kuoppala@linux.intel.com>
Reviewed-by: Prathap Kumar Valsan <prathap.kumar.valsan@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20191112223600.30993-4-chris@chris-wilson.co.uk

drivers/gpu/drm/i915/gt/intel_mocs.c

@@ -452,3 +452,7 @@ void intel_mocs_init(struct intel_gt *gt)
 	if (HAS_GLOBAL_MOCS_REGISTERS(gt->i915))
 		init_global_mocs(gt);
 }
+
+#if IS_ENABLED(CONFIG_DRM_I915_SELFTEST)
+#include "selftest_mocs.c"
+#endif