Sultan_defconfig: Disable overlay0 writeback

Derp, this breaks video playback with many apps, causing the phone to freeze. Thanks to Johnnyslt for pointing out my derp.
devices-msm8x60: Clean up GPU frequencies

Signed-off-by: Sultanxda <sultanxda@gmail.com>
bcmdhd: Remove signal hack
Sultan_defconfig: Update cfg80211 configuration from Grouper

Signed-off-by: Sultanxda <sultanxda@gmail.com>
vidc: Clean up memory-type references

Signed-off-by: Sultanxda <sultanxda@gmail.com>
Sultan_defconfig: v1.0.2