iio: adc: aspeed: Use devm_add_action_or_reset.

This patch use devm_add_action_or_reset to handle the error in probe
phase.

Signed-off-by: Billy Tsai <billy_tsai@aspeedtech.com>
Link: https://lore.kernel.org/r/20210922081520.30580-6-billy_tsai@aspeedtech.com


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