lint: Make lint work on Darwin

Darwin's getopt does not support the same parameters as the
util-linux version and so it is not possible to commit any
changes because lint fails.

Change-Id: Ife26083d2de080af9ed3d509945720051ca14bd7
Signed-off-by: Stefan Reinauer <stefan.reinauer@coreboot.org>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/80436
Reviewed-by: Felix Singer <service+coreboot-gerrit@felixsinger.de>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>

util/lint/lint

@@ -29,7 +29,14 @@ junit_write () {
 	fi
 }
 
-if ! cmd_args="$(getopt -l help,junit,invert -o hIJ -- "$@")"; then
+# Look if we have getopt. If not, build it.
+if [ $(uname) == Darwin ]; then
+  GETOPT="getopt hIJ"
+else
+  GETOPT="getopt -l help,junit,invert -o hIJ"
+fi
+
+if ! cmd_args="$($GETOPT -- "$@")"; then
 	usage
 	exit 0
 fi