ASoC: q6afe: Remove unused q6afe_is_rx_port() function

This reverts commit 4a957374 ("ASoc: q6afe: add support to get
port direction"), since the function is not needed anymore.

q6afe-dai already exposes the possible directions for a DAI through
the DAI capabilities (playback/capture-only DAI). Now we use
snd_soc_dai_link_set_capabilities() to infer the information
directly from the DAI capabilities.

Signed-off-by: Stephan Gerhold <stephan@gerhold.net>
Tested-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
Reviewed-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
Cc: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
Link: https://lore.kernel.org/r/20200723183904.321040-4-stephan@gerhold.net


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