regulator: stm32-vrefbuf: 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://lore.kernel.org/r/20191009150138.11640-1-yuehaibing@huawei.com
Signed-off-by: Mark Brown <broonie@kernel.org>
1 file changed