drivers: usb: Use Android device as USB keyboard/mouse [pelya]

Adapt to 3.4.y 8974/hammerhead
Base project: https://github.com/pelya/android-keyboard-gadget
Required app: https://play.google.com/store/apps/details?id=remote.hid.keyboard.client

Steps:
* Start ADB Debugging
* Start app
* Connect device to system via USB cable

All credits to @pelya for this sweet hack.

Signed-off-by: Pranav Vashi <neobuddy89@gmail.com>