usb: Kconfig: move ulpi bus support out of host

The ULPI bus is not only for host, but for device mode too, so move
it out from host's Kconfig.

Signed-off-by: Peter Chen <peter.chen@nxp.com>
Acked-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>