amvecm: fix factory mode test pattern abnormal LC effect [1/1]

PD#TV-5977

Problem:
customer platform, when LC is on, test pattern abnormal

Solution:
there is two frame delay for LC histogram, do not enable LC precess
before it is ready

Verify:
TL1

Change-Id: I78febb9f978dba44faff74677d84075fdf1fd8c7
Signed-off-by: Xihai Zhu <xihai.zhu@amlogic.com>

drivers/amlogic/media/enhancement/amvecm/local_contrast.c

@@ -1477,7 +1477,7 @@ void lc_process(struct vframe_s *vf,
 		return;
 	}
 
-	if (lc_flag == 0) {
+	if (lc_flag <= 1) {
 		lc_flag++;
 		return;
 	}