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_hw_intf.h

@@ -194,6 +194,13 @@ struct sde_hw_intf_ops {
 	void (*avr_ctrl)(struct sde_hw_intf *intf,
 			const struct intf_avr_params *avr_params);
 
+	/**
+	 * Indicates the AVR armed status
+	 *
+	 * @return: false if a trigger is pending, else true while AVR is enabled
+	 */
+	u32 (*get_avr_status)(struct sde_hw_intf *intf);
+
 	/**
 	 * Enable/disable 64 bit compressed data input to interface block
 	 */