clk: mediatek: mt6797: use devm_platform_ioremap_resource() to simplify code

Use devm_platform_ioremap_resource() to simplify the code a bit.
This is detected by coccinelle.

Signed-off-by: YueHaibing <yuehaibing@huawei.com>
Link: https://lkml.kernel.org/r/20191015124728.25072-1-yuehaibing@huawei.com


Signed-off-by: Stephen Boyd <sboyd@kernel.org>