Allow capital letters in mac address regex

This PS is to permit mac addresses that include capitals letters in the
range A-F.

Change-Id: Ib0ac54848cec9c7ae315614e61cbfb4d663fcce4
diff --git a/tempest/lib/api_schema/response/compute/v2_1/parameter_types.py b/tempest/lib/api_schema/response/compute/v2_1/parameter_types.py
index 8aed37d..b36c9d6 100644
--- a/tempest/lib/api_schema/response/compute/v2_1/parameter_types.py
+++ b/tempest/lib/api_schema/response/compute/v2_1/parameter_types.py
@@ -30,7 +30,7 @@
 
 mac_address = {
     'type': 'string',
-    'pattern': '(?:[a-f0-9]{2}:){5}[a-f0-9]{2}'
+    'pattern': '(?:[a-fA-F0-9]{2}:){5}[a-fA-F0-9]{2}'
 }
 
 ip_address = {