This patch adds mt8195 audio afe document.

In order to support dynamic clock reparenting for ADDA and ETDM, PLL
and MUX clocks are requested even though they are not consumed by afe
directly.
Signed-off-by: Trevor Wu <trevor.wu@mediatek.com>
Link: https://lore.kernel.org/r/20210819084144.18483-8-trevor.wu@mediatek.comSigned-off-by: Mark Brown <broonie@kernel.org>