rtc: sunplus: use devm_platform_ioremap_resource_byname()

Convert platform_get_resource_byname(),devm_ioremap_resource() to a single
call to devm_platform_ioremap_resource_byname(), as this is exactly what
this function does.

Signed-off-by: Ye Xingchen <ye.xingchen@zte.com.cn>
Link: https://lore.kernel.org/r/202303221131581039486@zte.com.cn


Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>