mfd: arizona: Hold device in reset while ramping supplies

Acquire the /RESET GPIO before we enable regulators and hold the device
in reset while the regulators power up in order to improve robustness
during the initial power up.

Also fix the error path so that the device is left in reset while we're
at it.

Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>