iio: proximity: sx_common: Use devm_regulator_bulk_get_enable()

This driver only turns the power for some regulators on at probe and off
via a custom devm_add_action_or_reset() callback. The new
devm_regulator_bulk_get_enable() replaces all this boilerplate code.

Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Cc: Gwendal Grignou <gwendal@chromium.org>
Reviewed-by: Stephen Boyd <swboyd@chromium.org>
Reviewed-by: Matti Vaittinen <mazziesaccount@gmail.com>
Reviewed-by: Nuno Sá <nuno.sa@analog.com>
Link: https://lore.kernel.org/r/20221016163409.320197-13-jic23@kernel.org