usb: host: ohci-pxa27x: propagate the irq error code

In several drivers in the pxa architecture, it was found that the
platform_get_irq() was not propagated. This breaks the the device-tree
probe deferral path, if -EPROBE_DEFER is returned. Unfortunately, the
error return in this case is transformed into -ENXIO, breaking the
deferral mechanism.

Even if in this specific case the driver was not broken, because the
interrupt controller is always probed before drivers, propagate the
proper return code.

Signed-off-by: Robert Jarzmik <robert.jarzmik@free.fr>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>