genirq: Generic chip: Add big endian I/O accessors

Use io{read,write}32be if the caller specified IRQ_GC_BE_IO when creating
the irqchip.

Signed-off-by: Kevin Cernekee <cernekee@gmail.com>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Acked-by: Arnd Bergmann <arnd@arndb.de>
Link: https://lkml.kernel.org/r/1415342669-30640-5-git-send-email-cernekee@gmail.com


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