Add "--always" option to the git describe command in tools

It seems that without that option our docs builds on readthedocs
are failing now. Git advices there to use "--always" option so lets
try that.

Change-Id: I90ccccb51e46353495e6cc42547a30b842d90805

tools/get_version.py

@@ -37,7 +37,7 @@ def get_version():
     version = CACHE.get('version')
     if not version:
         CACHE['version'] = version = common.execute(
-            f"git -C '{TOP_DIR}' describe").splitlines()[0]
+            f"git -C '{TOP_DIR}' describe --always").splitlines()[0]
     return version