main: update usage with logger option

src/main.c

@@ -154,6 +154,7 @@ static void usage(void)
 		"\t-p, --phys             Phys to manage\n"
 		"\t-P, --nophys           Phys to ignore\n"
 		"\t-d, --debug            Enable debug output\n"
+		"\t-l, --logger           Override default stderr logging\n"
 		"\t-v, --version          Show version\n"
 		"\t-h, --help             Show help options\n");
 }