bus: vexpress-config: Convert to devm_platform_ioremap_resource()

Use devm_platform_ioremap_resource() to simplify code.

Signed-off-by: Yangtao Li <frank.li@vivo.com>
Link: https://lore.kernel.org/r/20230706072042.31296-6-frank.li@vivo.com


Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>