util/getrevision.sh: Fallback when git tags is missing

If the tags are missing the version may not be evaluated correctly.

BUG=b:177691209
BRANCH=none
TEST=none

Change-Id: Ib9f85b2be8b6f5e1332ba98a8a71fcad12331818
Signed-off-by: Edward O'Callaghan <quasisec@google.com>
Reviewed-on: https://review.coreboot.org/c/flashrom/+/49618
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Patrick Georgi <pgeorgi@google.com>
Reviewed-by: Nico Huber <nico.h@gmx.de>

util/getrevision.sh

@@ -129,7 +129,7 @@ timestamp() {
 revision() {
 	local r
 	if git_is_file_tracked "$1" ; then
-		r=$(git describe $(git_last_commit "$1"))
+		r=$(git describe --always $(git_last_commit "$1"))
 		if git_has_local_changes "$1" ; then
 			r="$r-dirty"
 		fi