When wm8904 work in DSP mode B, we still need to configure it to
work in DSP mode. Or else, it will work in Right Justified mode.
Signed-off-by: Bo Shen <voice.shen@atmel.com> Acked-by: Charles Keepax <ckeepax@opensource.wolfsonmicro.com> Signed-off-by: Mark Brown <broonie@linaro.org> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>