disp: msm: sde: report AVR_STATUS in vsync_event sysfs node

Report the AVR_STATUS which indicates if there's a pending
trigger when Adaptive Variable Refresh feature is enabled.
This allows SW to detect whether the old frame is repeated
or if the new frame was taken when the trigger is very
close to Vsync.

Change-Id: I6b04482e5c4c3bb92bad426c529c1fd3612d41c3
Signed-off-by: Steve Cohen <cohens@codeaurora.org>

msm/sde/sde_encoder.h

@@ -392,6 +392,12 @@ enum sde_intf_mode sde_encoder_get_intf_mode(struct drm_encoder *encoder);
  */
 u32 sde_encoder_get_frame_count(struct drm_encoder *encoder);
 
+/**
+ * sde_encoder_get_avr_status - get combined avr_status from all intfs for given virt encoder
+ * @drm_enc: Pointer to drm encoder structure
+ */
+int sde_encoder_get_avr_status(struct drm_encoder *drm_enc);
+
 /*
  * sde_encoder_get_vblank_timestamp - get the last vsync timestamp
  * @encoder: Pointer to drm encoder object