regulator: s5m8767: Hand over GPIO to regulator core

The GPIO descriptors used by the S5M8767 driver are retrieved
during probe() and it is really helpful to have those under
devres management because of all the errorpaths in the
intialization.

Using the new dev_gpiod_unhinge() call we can remove the
devres management of the descriptor right before handing
it over to the regulators core.

Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Reviewed-by: Marek Szyprowski <m.szyprowski@samsung.com>
Tested-by: Marek Szyprowski <m.szyprowski@samsung.com>
Reviewed-by: Charles Keepax <ckeepax@opensource.cirrus.com>
Signed-off-by: Mark Brown <broonie@kernel.org>