clk: imx: imx8: add audio clock mux driver

The Audio Clock Mux (ACM) is a collection of control registers
and multiplexers that are used to route the audio source clocks
to the audio peripherals.

Each audio peripheral has its dedicated audio clock mux
(which differ based on usage) and control register.

Signed-off-by: Shengjiu Wang <shengjiu.wang@nxp.com>
Reviewed-by: Peng Fan <peng.fan@nxp.com>
Reviewed-by: Abel Vesa <abel.vesa@linaro.org>
Link: https://lore.kernel.org/r/1690260984-25744-3-git-send-email-shengjiu.wang@nxp.com


Signed-off-by: Abel Vesa <abel.vesa@linaro.org>