regulator: axp20x: Fix reference cout leak

[ Upstream commit e78bf6be7edaacb39778f3a89416caddfc6c6d70 ]

Decrements the reference count of device node and its child node.

Fixes: dfe7a1b0 ("regulator: AXP20x: Add support for regulators subsystem")
Signed-off-by: Pan Bian <bianpan2016@163.com>
Link: https://lore.kernel.org/r/20210120123313.107640-1-bianpan2016@163.com


Signed-off-by: Mark Brown <broonie@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>