ASoC: twl4030: Correct the support for Voice port

In order to be able to use the Voice port of twl4030 three bits need to be
handled in VOICE_IF register:
VIF_EN: to enable the voice port (needed for both playback and capture)
VIF_DIN_EN: Need to be enabled for playback only (input to the codec)
VIF_DOUT_EN: Need to be enabled for capture only (output from codec)

Use DAPM_SUPPLY for the VIF_EN bit and add DAPM_AIF_IO/OUT widget to handle
the playback/capture bit.

Signed-off-by: Peter Ujfalusi <peter.ujfalusi@ti.com>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>