imx6: kernel: add GW16082 miniPCI Expansion Mezzanine support

The GW16082 miniPCI Expansion Mezzanine has the INTA/B/C/D IRQ's reversed
from the PCI standard. This will soon be resolved in the bootloader via
devicetree, but in the meantime this will work around the issue.

Signed-off-by: Tim Harvey <tharvey@gateworks.com>

git-svn-id: svn://svn.openwrt.org/openwrt/trunk@42146 3c298f89-4303-0410-b956-a3cf2f4a3e73