usb: gadget: udc: gr_udc: Fix deferred probing

When platform_get_irq() fails, it may return -EPROBE_DEFER, which
suggested deferred probing, it is very important to propagate it
upstream. We cannot override it with other error code.

Commit ce753ad1

 ("platform: finally disallow IRQ0 in
platform_get_irq() and its ilk") makes sure IRQ0 is not returned.

Signed-off-by: Zhu Wang <wangzhu9@huawei.com>
Link: https://lore.kernel.org/r/20230804110005.97061-1-wangzhu9@huawei.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>