Current hdmi-codec driver is assuming that it will be registered
from HDMI driver. Because of this assumption, each callback function
has struct device pointer which is parent device (= HDMI).
Then, it can use dev_get_drvdata() to get private data.

OTOH, on some SoC/HDMI case, SoC has VIDEO/SOUND and HDMI IPs.
This case, it needs SoC VIDEO, SoC SOUND and HDMI video, HDMI codec
driver. In DesignWare HDMI IP case, SoC VIDEO (= DRM/KMS) driver tries
to bind DesignWare HDMI video driver, and HDMI codec driver
(= hdmi-codec). This case, above "parent device" of HDMI codec driver
is DRM/KMS driver and its "device" already has private data.

And, from DT and ASoC CPU/Codec/Card binding point of view, HDMI codec
(= hdmi-codec) needs to have "parent device" (= DRM/KMS), otherwise,
it never detect sound card.

Because of these reasons, some driver can't use dev_get_drvdata() to
get private data on hdmi-codec driver. This patch add new void pointer
on hdmi_codec_pdata for private data, and callback function will be
called with it.
Signed-off-by: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>
Signed-off-by: Mark Brown <broonie@kernel.org>