ASoC: sun8i-codec: Protect the clock rate while streams are open

ASoC: sun8i-codec: Protect the clock rate while streams are open

The codec's clock input is shared among all AIFs, and shared with other
audio-related hardware in the SoC, including I2S and SPDIF controllers.
To ensure sample rates selected by userspace or by codec2codec DAI links
are maintained, the clock rate must be protected while it is in use.

Signed-off-by: Samuel Holland <samuel@sholland.org>
Acked-by: Maxime Ripard <mripard@kernel.org>
Link: https://lore.kernel.org/r/20201014061941.4306-13-samuel@sholland.org
Signed-off-by: Mark Brown <broonie@kernel.org>