V210 issue fix + correct packing

cmd/mxl-pattern/main.go

@@ -146,9 +146,8 @@ func validateVideoArgs(args *appArgs) error {
 	if args.videoFlowDefFile != "" {
 		return nil
 	}
-	if args.videoWidth == 0 || args.videoWidth%6 != 0 {
-		// v210 stores 6 pixels in each 16-byte block.
-		return fmt.Errorf("video width must be greater than zero and divisible by 6")
+	if args.videoWidth == 0 || args.videoWidth%2 != 0 {
+		return fmt.Errorf("video width must be greater than zero and even for 4:2:2 video")
 	}
 	if args.videoHeight == 0 {
 		return fmt.Errorf("video height must be greater than zero")