irqchip/mbigen: Fix memory mapping code

Some mbigens share memory regions, and devm_ioremap_resource
does not allow to share resources which will break the probe
of mbigen, in opposition to devm_ioremap.

This patch restores back usage of devm_ioremap function, but
with proper error handling and logging.

Fixes: 216646e4 ("irqchip/mbigen: Fix return value check in mbigen_device_probe()")
Signed-off-by: Hanjun Guo <hanjun.guo@linaro.org>
Acked-by: Marc Zyngier <marc.zyngier@arm.com>
Cc: Kefeng Wang <wangkefeng.wang@huawei.com>
Cc: linuxarm@huawei.com
Cc: Wei Yongjun <weiyongjun1@huawei.com>
Cc: MaJun <majun258@huawei.com>
Link: http://lkml.kernel.org/r/1494561328-39514-2-git-send-email-guohanjun@huawei.com


Signed-off-by: Thomas Gleixner <tglx@linutronix.de>