ARM: ux500: switch from gic_arch_extn to gic_set_irqchip_flags

Instead of directly touching gic_arch_extn, which is about to
be removed, use gic_set_irqchip_flags instead.

Acked-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Link: https://lkml.kernel.org/r/1426088737-15817-4-git-send-email-marc.zyngier@arm.com


Signed-off-by: Jason Cooper <jason@lakedaemon.net>