ASoC: tlv320aic3x: Let the codec hit SND_SOC_BIAS_OFF when idle

Now codec hits the SND_SOC_BIAS_OFF also when it is idle. This is also
the default state after probing and codec is left unconfigured and
unpowered by default. Initialization will happen when the bias state changes
and aic3x_set_power does power-up and cache sync.

Signed-off-by: Jarkko Nikula <jhnikula@gmail.com>
Acked-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Signed-off-by: Liam Girdwood <lrg@slimlogic.co.uk>