Bump version of stackhpc.dell-powerconnect-switch

Version v1.1.0 includes useful updates needed for supporting the
PowerConnect 6248, such as support for 'enable' and quirky differences
in the CLI.

Change-Id: I1a9e0471f34183c85002de30c395b82baa5f3ef4

requirements.yml

@@ -16,7 +16,7 @@
 - src: singleplatform-eng.users
   version: v1.2.5
 - src: stackhpc.dell-powerconnect-switch
-  version: v1.0.0
+  version: v1.1.0
 - src: stackhpc.drac
   version: 1.1.4
 - src: stackhpc.drac-facts