The PCI controllers in the AR71XX and in the
AR724X SoCs are different, and both of them
uses different IRQ wiring.

The patch modifies the 'pcibios_map_irq' function
in order to allow to use different IRQ maps for
the different SoCs. The patch also adds a function,
which lets the board setup code to override the
default IRQ map.
Signed-off-by: Gabor Juhos <juhosg@openwrt.org>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/3500/Signed-off-by: Ralf Baechle <ralf@linux-mips.org>