drm/i915: No need to power up PG2 for GMBUS on BXT

GMBUS lives in PG1, so no need to power up PG2. We do want to prevent
the DMC from making a mess of things though, so add GMBUS to the DC off
power well.

Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20171208213739.16388-2-ville.syrjala@linux.intel.com
Reviewed-by: Dhinakaran Pandiyan <dhinakaran.pandiyan@intel.com>

drivers/gpu/drm/i915/intel_runtime_pm.c

@@ -1726,13 +1726,13 @@ void intel_display_power_put(struct drm_i915_private *dev_priv,
 	BIT_ULL(POWER_DOMAIN_AUX_C) |			\
 	BIT_ULL(POWER_DOMAIN_AUDIO) |			\
 	BIT_ULL(POWER_DOMAIN_VGA) |				\
-	BIT_ULL(POWER_DOMAIN_GMBUS) |			\
 	BIT_ULL(POWER_DOMAIN_INIT))
 #define BXT_DISPLAY_DC_OFF_POWER_DOMAINS (		\
 	BXT_DISPLAY_POWERWELL_2_POWER_DOMAINS |		\
 	BIT_ULL(POWER_DOMAIN_GT_IRQ) |			\
 	BIT_ULL(POWER_DOMAIN_MODESET) |			\
 	BIT_ULL(POWER_DOMAIN_AUX_A) |			\
+	BIT_ULL(POWER_DOMAIN_GMBUS) |			\
 	BIT_ULL(POWER_DOMAIN_INIT))
 #define BXT_DPIO_CMN_A_POWER_DOMAINS (			\
 	BIT_ULL(POWER_DOMAIN_PORT_DDI_A_LANES) |		\