iio: dac: vf610: Use devm_platform_ioremap_resource

Reduce local boilerplate.
Suggested by coccinelle

CHECK   drivers/iio/dac/vf610_dac.c
drivers/iio/dac/vf610_dac.c:189:1-11: WARNING: Use devm_platform_ioremap_resource for info -> regs

Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Reviewed-by: Alexandru Ardelean <alexandru.ardelean@analog.com>
Cc: Sanchayan Maity <maitysanchayan@gmail.com>