drm/i915: add dev_priv to intel_gmbus

This way we can free up the bus->adaptor.algo_data pointer and make it
available for use with the bitbanging fallback algo.

Reviewed-by: Eugeni Dodonov <eugeni.dodonov@intel.com>
Signed-Off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
index 35833fc..3cc2694 100644
--- a/drivers/gpu/drm/i915/i915_drv.h
+++ b/drivers/gpu/drm/i915/i915_drv.h
@@ -298,6 +298,13 @@
 struct intel_fbdev;
 struct intel_fbc_work;
 
+struct intel_gmbus {
+	struct i2c_adapter adapter;
+	struct i2c_adapter *force_bit;
+	u32 reg0;
+	struct drm_i915_private *dev_priv;
+};
+
 typedef struct drm_i915_private {
 	struct drm_device *dev;
 
@@ -315,11 +322,7 @@
 	/** gt_lock is also taken in irq contexts. */
 	struct spinlock gt_lock;
 
-	struct intel_gmbus {
-		struct i2c_adapter adapter;
-		struct i2c_adapter *force_bit;
-		u32 reg0;
-	} *gmbus;
+	struct intel_gmbus *gmbus;
 
 	/** gmbus_mutex protects against concurrent usage of the single hw gmbus
 	 * controller on different i2c buses. */