staging: iio: ad9832: Use devm_regulator_get_enable()

The regulators are only enabled at probe(), hence replace the boilerplate
code by making use of devm_regulator_get_enable() helper.

Signed-off-by: Saalim Quadri <danascape@gmail.com>
Link: https://patch.msgid.link/20250306000040.1550656-1-danascape@gmail.com


Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>