Revert "add Custom Lockscreen switch"

This reverts commit 76e5f3cca230bb50ccb164794c90b780d37d482a.

Conflicts:
	res/xml/lockscreen_interface_settings.xml
	src/com/android/settings/cyanogenmod/LockscreenInterface.java

Change-Id: Ia824d29b15243609d8c1b990959264cdc504f4a4