usb: gadget: at91-udc: fix irq and iomem resource retrieval

commit 886c7c426d465732ec9d1b2bbdda5642fc2e7e05 upstream.

When using dt resources retrieval (interrupts and reg properties) there is
no predefined order for these resources in the platform dev resource
table. Also don't expect the number of resource to be always 2.

Signed-off-by: Jean-Jacques Hiblot <jjhiblot@traphandler.com>
Acked-by: Boris BREZILLON <b.brezillon@overkiz.com>
Acked-by: Nicolas Ferre <nicolas.ferre@atmel.com>
Signed-off-by: Felipe Balbi <balbi@ti.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>