[INTERNAL] sap.m.SplitButton: Add restricted tag
[INTERNAL] sap.m.SplitButton: Add restricted tag

The SplitButton control is used in richtexteditor's ToolbarWrapper
and in sap.m.MenuButton hence the restricted tag is added

Change-Id: Iffae8204a5c1c7e4f918e8aa9b6a77d106405f2e

SAP/openui5,cschuff/openui5,SAP/openui5,cschuff/openui5,SAP/openui5,cschuff/openui5,SAP/openui5