USB: ccid_bridge: Drop the usb device reference upon disconnect

usb device ref count is incremented in probe via usb_get_dev. Call
usb_put_dev during disconnect to drop the ref count. Otherwise
struct usb_device memory is leaked.

Change-Id: Ia82f5ff7ef1a0a5e5c54f6e52b9e22f8434c45a6
Signed-off-by: Pavankumar Kondeti <pkondeti@codeaurora.org>