Modify devstack-base to allow for fips

devstack-base is changed to descend from
openstack-multinode-fips which is defined in
project-config.

This allows jobs to execute the enable_fips playbook
to enable FIPS mode on the node, but only if they
opt-in by setting enable_fips to True.  Otherwise,
this is a no-op.

Change-Id: I5631281662dbd18056ffba291290ed0978ab937e
diff --git a/functions-common b/functions-common
index 4eed5d8..844fffa 100644
--- a/functions-common
+++ b/functions-common
@@ -2545,6 +2545,11 @@
     fi
 }
 
+function is_fips_enabled {
+    fips=`cat /proc/sys/crypto/fips_enabled`
+    [ "$fips" == "1" ]
+}
+
 # Restore xtrace
 $_XTRACE_FUNCTIONS_COMMON