drm/i915/vblank: use intel_de_read()

Use the intel_de_* functions for display registers.

Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by: Arun R Murthy <arun.r.murthy@intel.com>
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Reviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/ecfac5ebddcb46be1ddf2e34e52648fbf9fa4ca6.1673873708.git.jani.nikula@intel.com

drivers/gpu/drm/i915/display/intel_vblank.c

@@ -137,7 +137,7 @@ u32 g4x_get_vblank_counter(struct drm_crtc *crtc)
 	if (!vblank->max_vblank_count)
 		return 0;
 
-	return intel_uncore_read(&dev_priv->uncore, PIPE_FRMCOUNT_G4X(pipe));
+	return intel_de_read(dev_priv, PIPE_FRMCOUNT_G4X(pipe));
 }
 
 static u32 intel_crtc_scanlines_since_frame_timestamp(struct intel_crtc *crtc)