ASoC: wm8904: add dt ids table

The WM8904 and WM8918 has the same data type, while the WM8912
has different data type. So, use the data in dt ids table to
distinguish them.

Signed-off-by: Alexander Morozov <linux@meltdown.ru>
[voice.shen@atmel.com: add code to distinguish device type]
Signed-off-by: Bo Shen <voice.shen@atmel.com>
Signed-off-by: Mark Brown <broonie@kernel.org>