Remove unneeded error handling on the result of a call
to platform_get_resource() when the value is passed to
devm_ioremap_resource().

And use devm_platform_get_and_ioremap_resource() to simplify
code.
Signed-off-by: NYang Yingliang <yangyingliang@huawei.com>
Signed-off-by: NThomas Bogendoerfer <tsbogend@alpha.franken.de>