ARM: imx: fix build failure concerning otg/ulpi

The build failure was introduced by

	13dd0c97

 (USB: otg/ulpi: extend the generic ulpi driver.)

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Acked-by: Igor Grinberg <grinberg@compulab.co.il>
Cc: Mike Rapoport <mike@compulab.co.il>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>