ASoC: tlv320aic32x4: Add support for tlv320aic32x6

Add support for the tlv320aic32x6 family of devices.
These devices share the same register set as the tlv320aic32x4
and this driver can be re-used.

TLV320aic32x6 data sheets are here:
tlv320aic3256 - http://www.ti.com/lit/gpn/tlv320aic3256
tlv320aic3206 - http://www.ti.com/lit/gpn/tlv320aic3206



Signed-off-by: Dan Murphy <dmurphy@ti.com>
Signed-off-by: Mark Brown <broonie@kernel.org>