drm/i915: Add a modeset power domain

We need a power domain for disabling DC5/DC6 around modesets to prevent
confusing the DMC.

Signed-off-by: Patrik Jakobsson <patrik.jakobsson@linux.intel.com>
Reviewed-by: Imre Deak <imre.deak@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1447084107-8521-8-git-send-email-patrik.jakobsson@linux.intel.com
diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
index 6683bd1..d0dccef 100644
--- a/drivers/gpu/drm/i915/i915_drv.h
+++ b/drivers/gpu/drm/i915/i915_drv.h
@@ -196,6 +196,7 @@
 	POWER_DOMAIN_AUX_C,
 	POWER_DOMAIN_AUX_D,
 	POWER_DOMAIN_GMBUS,
+	POWER_DOMAIN_MODESET,
 	POWER_DOMAIN_INIT,
 
 	POWER_DOMAIN_NUM,