drm: Pass the display mode to drm_calc_timestamping_constants()

We don't really use hwmode anymore in i915, so eliminating its use
from the core code seems prudent. Just pass the appropriate mode
to drm_calc_timestamping_constants().

Reviewed-by: mario.kleiner.de@gmail.com
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c
index e77d4b8..920fcff 100644
--- a/drivers/gpu/drm/i915/intel_display.c
+++ b/drivers/gpu/drm/i915/intel_display.c
@@ -9693,7 +9693,8 @@
 		 * are later needed by vblank and swap-completion
 		 * timestamping. They are derived from true hwmode.
 		 */
-		drm_calc_timestamping_constants(crtc);
+		drm_calc_timestamping_constants(crtc,
+						&pipe_config->adjusted_mode);
 	}
 
 	/* FIXME: add subpixel order */