drm/i915: use dev_priv for the FBC functions

Because the cool kids use dev_priv and FBC wants to be cool too.

We've been historically using struct drm_device on the FBC function
arguments, but we only really need it for intel_vgpu_active(): we can
use dev_priv everywhere else. So let's fully switch to dev_priv since
I'm getting tired of adding "struct drm_device *dev = dev_priv->dev"
everywhere.

If I get a NACK here I'll propose the opposite: convert all the
functions that currently take dev_priv to take dev.

Signed-off-by: Paulo Zanoni <paulo.r.zanoni@intel.com>
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
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 79d7ece..7f75ff3 100644
--- a/drivers/gpu/drm/i915/i915_drv.h
+++ b/drivers/gpu/drm/i915/i915_drv.h
@@ -937,9 +937,9 @@
 		FBC_ROTATION, /* rotation is not supported */
 	} no_fbc_reason;
 
-	bool (*fbc_enabled)(struct drm_device *dev);
+	bool (*fbc_enabled)(struct drm_i915_private *dev_priv);
 	void (*enable_fbc)(struct drm_crtc *crtc);
-	void (*disable_fbc)(struct drm_device *dev);
+	void (*disable_fbc)(struct drm_i915_private *dev_priv);
 };
 
 /**