irqchip: armada-370-xp: Introduce a is_percpu_irq() helper for readability

This commit introduces a helper function is_percpu_irq(), to be used
when interrupts are mapped to decide which ones are set as per CPU.

This change will allow to extend the list of per cpu interrupts in a less
intrusive fashion; also, it makes the code slightly more readable by keeping
a list of the per CPU interrupts.

Signed-off-by: Ezequiel Garcia <ezequiel.garcia@free-electrons.com>
Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
Acked-by: Gregory CLEMENT <gregory.clement@free-electrons.com>
Link: https://lkml.kernel.org/r/1425379400-4346-3-git-send-email-maxime.ripard@free-electrons.com


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