firmware-utils: The option -F was not detected.

This was missing in r22396

This fixes build of brcm47xx


git-svn-id: svn://svn.openwrt.org/openwrt/trunk@22398 3c298f89-4303-0410-b956-a3cf2f4a3e73

tools/firmware-utils/src/trx.c

@@ -119,7 +119,7 @@ int main(int argc, char **argv)
 	in = NULL;
 	i = 0;
 
-	while ((c = getopt(argc, argv, "-:2o:m:a:x:b:f:A:")) != -1) {
+	while ((c = getopt(argc, argv, "-:2o:m:a:x:b:f:A:F:")) != -1) {
 		switch (c) {
 			case '2':
 				/* take care that nothing was written to buf so far */