arm: add black screen in channel swiching

libarmbox/video_lib.h

@@ -145,6 +145,7 @@ typedef enum
 	VIDEO_CONTROL_BLUE_BOOST,
 	VIDEO_CONTROL_DYNAMIC_CONTRAST,
 	VIDEO_CONTROL_SCALER_SHARPNESS,
+	VIDEO_CONTROL_ZAPPING_MODE,
 	VIDEO_CONTROL_MAX = VIDEO_CONTROL_SHARPNESS
 } VIDEO_CONTROL;
 
@@ -187,6 +188,7 @@ class cVideo
 		int blue_boost;
 		int dynamic_contrast;
 		int scaler_sharpness;
+		int zapping_mode;
 
 		/* used internally by dmx */
 		int64_t GetPTS(void);