DeviceSettings: option for Long Tap Logo sleep or Normal button.

Adding option to let user select whether logo long tap is used
as a long tap Menu button event, or as a way to switch screen off.

Adding ramdisk change needed for the sysfs toggle.

Requires kernel change in this review: http://review.cyanogenmod.org/37577

Change-Id: Ic6c4b5c2083445b0993c63b4624d0afdbb02ec57