usb: gadget: r8a66597: convert to devm_platform_ioremap_resource_byname

Use devm_platform_ioremap_resource_byname() to simplify code

Signed-off-by: Chunfeng Yun <chunfeng.yun@mediatek.com>
Link: https://lore.kernel.org/r/1595404275-8449-5-git-send-email-chunfeng.yun@mediatek.com


Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>