ASoC: tlv320aic31xx: Do not ignore errors in aic31xx_device_init()

We need to return the error codes from aic31xx_device_init() and return
from the i2c_probe with the error code.
We will have kernel panic (NULL pointer dereference) in
regulator_register_notifier() in case the devm_regulator_bulk_get() fails
(with -EPROBE_DEFER for example).

Signed-off-by: Peter Ujfalusi <peter.ujfalusi@ti.com>
Signed-off-by: Mark Brown <broonie@linaro.org>
Cc: stable@vger.kernel.org