imx: ventana: add dt fixup for GW16082 irq mapping

imx: ventana: add dt fixup for GW16082 irq mapping

The GW16082 mini-PCI expansion mezzanine uses a TI XIO2001 PCIe-to-PCI
bridge with legacy INTA/B/C/D interrupts. These interrupts are assigned
in the reverse order according to the PCI spec.

If the TI bridge is found on the Ventana PCI bus, add device-tree nodes
according to bus enumeration explicitly defining the interrupt mapping
to override the default PCI mapping in the Linux kernel. This allows
the GW16082 to work with upstream kernels that support device-tree
irq parsing.

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