uboot-phytec

setlocalversion: add some more fallbacks for git describe

If working out of a custom git tree that lacks annotated tags, the
'git describe' operation spews "fatal: cannot describe" errors all
over the place.  So add some fallback code in case the best naming
was unable to locate something useful.

Signed-off-by: Mike Frysinger <vapier@gentoo.org>