rhine: Blank framebuffer to clear Sony boot splash

Change-Id: If55a9c1e66c17f8005b3c1f49961fc57706f6613
Revert "Workaround for blanking splash screen during boot"

This reverts commit 1e49248d6ce9cb40272a8800cbd40c1b0bba0fd5.
Merge branch 'cm-11.0' of https://github.com/CyanogenMod/android_device_sony_rhine-common into android-4.4