thermal/drivers/st: Use devm_platform_get_and_ioremap_resource()

Use devm_platform_get_and_ioremap_resource() to simplify
code and remove error message which within
devm_platform_get_and_ioremap_resource() already.

Signed-off-by: Yang Yingliang <yangyingliang@huawei.com>
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Link: https://lore.kernel.org/r/20210605120205.2459578-1-yangyingliang@huawei.com