Document required cmake options for unlocking to work on OpenSUSE (12.1 and later, at least)

kdesrc-buildrc-sample

@@ -247,6 +247,11 @@ module-set
                 kde-baseapps kate konsole
 end module-set
 
+# On OpenSUSE, for unlocking to work, you need to do this:
+#module kde-workspace
+  #cmake-options -DKDE4_COMMON_PAM_SERVICE=xdm -DKDE4_KCHECKPASS_PAM_SERVICE=xdm
+#end module
+
 # KDE/kde-wallpapers contains all wallpapers for your desktop
 module kde-wallpapers
 end module