staging/westbridge: convert cyasgadget to new udc core

This is not compile tested as I failed at it. I added an #if 0 block
because I did not find the struct device of the device.

Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>