[media] au0828: Make the s_reg and g_reg advanced debug calls work against the bridge

The g_reg and s_reg calls worked properly if acting on subdev registers
(such as the au8522), but didn't work against the au0828 itself.  Copy
the logic over from em28xx.

Signed-off-by: Devin Heitmueller <dheitmueller@kernellabs.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>

drivers/media/video/au0828/au0828-video.c

@@ -1717,8 +1717,12 @@ static int vidioc_g_register(struct file *file, void *priv,
 		v4l2_device_call_all(&dev->v4l2_dev, 0, core, g_register, reg);
 		return 0;
 	default:
-		return -EINVAL;
+		if (!v4l2_chip_match_host(&reg->match))
+			return -EINVAL;
 	}
+
+	reg->val = au0828_read(dev, reg->reg);
+	return 0;
 }
 
 static int vidioc_s_register(struct file *file, void *priv,
@@ -1732,9 +1736,10 @@ static int vidioc_s_register(struct file *file, void *priv,
 		v4l2_device_call_all(&dev->v4l2_dev, 0, core, s_register, reg);
 		return 0;
 	default:
-		return -EINVAL;
+		if (!v4l2_chip_match_host(&reg->match))
+			return -EINVAL;
 	}
-	return 0;
+	return au0828_writereg(dev, reg->reg, reg->val);
 }
 #endif