Allow interface type value none (#9098)

This PR allow user to set none value to interface type. So there is a way to achieve the goal via CLI:

config interface type XXX none
config interface speed XXX 10000
config interface type XXX CR

src/sonic-yang-models/yang-models/sonic-types.yang

@@ -151,6 +151,7 @@ module sonic-types {
             enum XAUI;
             enum XFI;
             enum XGMII;
+            enum none;
         }
     }