usb: gadget: udc: bcm63xx: propagate errors from platform_get_irq()

The driver overrides the error codes returned by platform_get_irq() to
-ENXIO for some strange reason.  Switch to propagating the error codes
upstream.

Acked-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: Sergey Shtylyov <s.shtylyov@omp.ru>
Link: https://lore.kernel.org/r/20211214204247.7172-2-s.shtylyov@omp.ru
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>