ARM: ux500: use symbolic names for interrupt flags

This switches to including <dt-bindings/interrupt-controller/irq.h>
and referencing the apropriate flags from there instead of
open-coding the flag numerals everywhere in the ux500 device
trees.

Acked-by: Lee Jones <lee.jones@linaro.org>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>