e: desklock config: use an enum instead of hardcoded values
e: desklock config: use an enum instead of hardcoded values

SVN revision: 73938

tasn/enlightenment,tizenorg/platform.upstream.enlightenment,FlorentRevest/Enlightenment,FlorentRevest/Enlightenment,tasn/enlightenment,FlorentRevest/Enlightenment,rvandegrift/e,tizenorg/platform.upstream.enlightenment,tasn/enlightenment,rvandegrift/e,rvandegrift/e,tizenorg/platform.upstream.enlightenment