UBUNTU: SAUCE: irqchip: mbigen: introduce mbigen_of_create_domain()

UBUNTU: SAUCE: irqchip: mbigen: introduce mbigen_of_create_domain()

Introduce mbigen_of_create_domain() to consolidate OF related
code and prepare for ACPI later, no funtional change.

Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com>
Signed-off-by: Hanjun Guo <hanjun.guo@linaro.org>
Reviewed-by: Ma Jun <majun258@huawei.com>
Tested-by: Ming Lei <ming.lei@canonical.com>
Tested-by: Wei Xu <xuwei5@hisilicon.com>
Cc: Marc Zyngier <marc.zyngier@arm.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
[v8 submission from:
 https://www.spinics.net/lists/arm-kernel/msg555522.html ]
BugLink: http://bugs.launchpad.net/bugs/1669061
Signed-off-by: dann frazier <dann.frazier@canonical.com>
Signed-off-by: Seth Forshee <seth.forshee@canonical.com>