ASoC: codecs: wcd938x: fix incorrect used of portid

Mixer controls have the channel id in mixer->reg, which is not same
as port id. port id should be derived from chan_info array.
So fix this. Without this, its possible that we could corrupt
struct wcd938x_sdw_priv by accessing port_map array out of range
with channel id instead of port id.

Fixes: e8ba1e05

 ("ASoC: codecs: wcd938x: add basic controls")
Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
Link: https://lore.kernel.org/r/20220126113549.8853-2-srinivas.kandagatla@linaro.org


Signed-off-by: Mark Brown <broonie@kernel.org>