ARM: Orion: DT support for IRQ and GPIO Controllers

Both IRQ and GPIO controllers can now be represented in DT.  The IRQ
controllers are setup first, and then the GPIO controllers. Interrupts
for GPIO lines are placed directly after the main interrupts in the
interrupt space.

Signed-off-by: Andrew Lunn <andrew@lunn.ch>
Acked-by: Sebastian Hesselbarth <sebastian.hesselbarth@googlemail.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Tested-by: Josh Coombs <josh.coombs@gmail.com>
Tested-by: Simon Baatz <gmbnomis@gmail.com>