drivers: usb: Use Android device as USB keyboard/mouse

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>

Conflicts:
	drivers/usb/gadget/android.c

Conflicts:
	drivers/usb/gadget/android.c
USB KEYBOARD/MOUSE: Added on/off trigger to driver. READ MORE.

When was ON by default I have seen that USB is always HID device.

And i have always received 2 connection sounds and vibrate...

It's annoying! so now all good, one alert for connection, and USB
is Android Device, and when I have connect USB Keyboard or mouse or both
via wireless connector (Microsoft keyboard + mouse Infra-Red)

it's works! phone detect mouse + keyboard and i can use them on screen!

the On/off trigger seems not needed to use the HID and can be OFF.

I have left it for future use, for compatibility if needed.