regulator: arizona-ldo1: Use correct device to get enable GPIO

Currently the enable GPIO is being looked up on the regulator
device itself but that does not have its own DT node, this causes
the lookup to fail and the regulator not to get its GPIO. The DT
node is shared across the whole MFD and as such the lookup needs
to happen on that parent device. Moving the lookup to the parent
device also means devres can no longer be used as the life time
would attach to the wrong device.

Additionally, the enable GPIO is active high so we should be passing
GPIOD_OUT_LOW to ensure the regulator starts in its off state allowing
the driver to enable it when it is ready.

Fixes: e1739e86 ("regulator: arizona-ldo1: Look up a descriptor and pass to the core")
Reported-by: Matthias Reichl <hias@horus.com>
Signed-off-by: Charles Keepax <ckeepax@opensource.cirrus.com>
Signed-off-by: Mark Brown <broonie@kernel.org>