sh: fix USBF resource for sh7722

The USBF function on sh7722 is currently not working with the m66592_udc
driver. The driver is using platform_get_resource_byname() so my commit
a0d29798e568116aa6c32aef7bab2d9e620c88ad broke sh7722 support.

The long term fix is to replace platform_get_resource_byname() in the
driver with platform_get_resource(), but this helps until that happens.

Signed-off-by: Magnus Damm <damm@igel.co.jp>
Signed-off-by: Paul Mundt <lethal@linux-sh.org>