ASoC: OMAP: HDMI: Correct signature of ASoC functions

These functions require access to IP-secific data. However, it is not possible
to pass such data as a function argument as such functions have a specific
signature specified by ASoC. Instead, they will have access to the IP-specific
data by calling snd_soc_codec_get_drvdata. The codec driver data is set
at probe time.

Signed-off-by: Ricardo Neri <ricardo.neri@ti.com>
Signed-off-by: Tomi Valkeinen <tomi.valkeinen@ti.com>