V4L/DVB: v4l2-common: add ability to use v4l2_ctrl_query_fill for chroma gain

Add the ability to use the v4l2_ctrl_query_fill() function for the newly
introduced chroma gain control.

Also, make use of the centralized function by the one caller.

This work was sponsored by EyeMagnet Limited.

Signed-off-by: Devin Heitmueller <dheitmueller@kernellabs.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
diff --git a/drivers/media/video/saa7115.c b/drivers/media/video/saa7115.c
index f96071c..72eaa66 100644
--- a/drivers/media/video/saa7115.c
+++ b/drivers/media/video/saa7115.c
@@ -1234,16 +1234,7 @@
 	case V4L2_CID_CHROMA_AGC:
 		return v4l2_ctrl_query_fill(qc, 0, 1, 1, 1);
 	case V4L2_CID_CHROMA_GAIN:
-		qc->type = V4L2_CTRL_TYPE_INTEGER;
-		qc->flags = V4L2_CTRL_FLAG_SLIDER;
-		qc->minimum = 0;
-		qc->maximum = 127;
-		qc->step = 1;
-		qc->default_value = 0x30;
-		qc->reserved[0] = 0;
-		qc->reserved[1] = 0;
-		strlcpy(qc->name, "chroma_gain", sizeof(qc->name));
-		return 0;
+		return v4l2_ctrl_query_fill(qc, 0, 127, 1, 48);
 	default:
 		return -EINVAL;
 	}