i3c: master: dw: convert to devm_platform_ioremap_resource

Use devm_platform_ioremap_resource() to simplify code.

Signed-off-by: Yangtao Li <tiny.windzz@gmail.com>
Acked-by: Vitor Soares <vitor.soares@synopsys.com>
Signed-off-by: Boris Brezillon <boris.brezillon@collabora.com>