add hash for locally emerged builds

When the EC is built using "emerge-<board> chromeos-ec" on a developer
workstation with the chromeos-ec package "cros-worked'on", put
"1.1.9999-<git-sha1>" rather than "no_version" in the version string.

Emerge is exporting the current git SHA-1 hash in the VCSID id but the
.git repository is not available during the build.

Signed-off-by: Vincent Palatin <vpalatin@chromium.org>

BRANCH=none
BUG=none
TEST=try the following build setups:
- local emerge
$ emerge-smaug chromeos-ec
$ strings /build/smaug/firmware/ec.bin | grep ryu
ryu_p4p5_1.1.9999-ebe18ef
- local build
$ make BOARD=ryu_p4p5
$ strings build/ryu_p4p5/ec.bin | grep ryu
ryu_p4p5_v1.1.3127-ebe18ef-dirt
- trybot build
$ cbuildbot --remote -g 270554 smaug-firmware
$ tar xvjf firmware_from_sources.tar.bz2
$ strings ec.bin | grep ryu
ryu_p4p5_v1.1.3137-9b52578

Change-Id: I386f80d82d95b5e99a1660a1eb242c47c54d17ef
Reviewed-on: https://chromium-review.googlesource.com/270554
Trybot-Ready: Vincent Palatin <vpalatin@chromium.org>
Tested-by: Vincent Palatin <vpalatin@chromium.org>
Reviewed-by: Randall Spangler <rspangler@chromium.org>
Commit-Queue: Vincent Palatin <vpalatin@chromium.org>

util/getversion.sh

@@ -26,7 +26,13 @@ if ghash=`git rev-parse --short --verify HEAD 2>/dev/null`; then
 	dirty=`sh -c "[ '$(git diff-index --name-only HEAD)' ] && echo '-dirty'"`
 	vbase="${ver_major}.${ver_branch}.${numcommits}-${ghash}${dirty}"
 else
-	vbase="no_version"
+	# Fall back to the VCSID provided by the packaging system if available.
+	if ghash=${VCSID##*-}; then
+		vbase="1.1.9999-${ghash:0:7}"
+	else
+		# then ultimately fails to "no_version"
+		vbase="no_version"
+	fi
 fi
 
 ver="${BOARD}_${vbase}"