FP4: overlay: Set physical power button and fps location

This sets config_is_powerbutton_fps, since the device has
fps embedded in the power button. It makes frameworks report that
fingerprint sensor is located on the side of the device, which
can be observed when enrolling a fingerprint for the first time.

Change-Id: Ifa079488db642c8a470e40cb585c08e9c85d7cf4