Use devm_platform_ioremap_resource_byname() to simplify code

Cc: Nagarjuna Kristam <nkristam@nvidia.com>
Signed-off-by: Chunfeng Yun <chunfeng.yun@mediatek.com>
Link: https://lore.kernel.org/r/1595404275-8449-6-git-send-email-chunfeng.yun@mediatek.comSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>