smdk4412: use sysfs for vsync notification

Change-Id: I6145c150c14825e767a6ef986993d5bbadd42853
Merge "smdk4412: use sysfs for vsync notification" into cm-10.1
Merge branch 'cm-10.1' of git://github.com/CyanogenMod/android_device_samsung_smdk4412-common into cm-10.1