Switch board_status.sh to use main branch

... so we can switch coreboot over.

Change-Id: Ib0487014fd49829e0d021533b04df9e8bd1a757a
Signed-off-by: Stefan Reinauer <stefan.reinauer@coreboot.org>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/75779
Reviewed-by: Martin L Roth <gaumless@gmail.com>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Nicholas Chin <nic.c3.14@gmail.com>

util/board_status/getrevision.sh

@@ -123,7 +123,7 @@ tagged_revision() {
 upstream_revision() {
 	local r=
 
-	r=$(git log remotes/origin/master -1 --format=format:%h)
+	r=$(git log remotes/origin/main -1 --format=format:%h)
 
 	if [ -z "$r" ]; then
 		r="unknown" # default to unknown