USB: ulpi: fix compilation warning

Fixes below compilation warning from ulpi.h

include/linux/usb/ulpi.h:145:
        warning: 'struct otg_io_access_ops' declared inside parameter list
include/linux/usb/ulpi.h:145:
         warning: its scope is only this definition or declaration,
         which is probably not what you want

Signed-off-by: Ajay Kumar Gupta <ajay.gupta@ti.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>