irqchip: gic: Replace hex numbers with defines.

This is to cleanup some hex numbers used in the code and replace
them with defines to make the code cleaner.

Signed-off-by: Feng Kan <fkan@apm.com>
Reviewed-by: Anup Patel <apatel@apm.com>
Link: https://lkml.kernel.org/r/1406757419-18729-2-git-send-email-fkan@apm.com


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