MLK-23906-1: ASoC: fsl_aud2htx: Don't bind clock with regmap

MLK-23906-1: ASoC: fsl_aud2htx: Don't bind clock with regmap

The call flow:
devm_regmap_init_mmio_clk
   - clk_prepare()
      - clk_pm_runtime_get()

Cause the power domain of bus clock always be enabled.
which impact the power consumption.

So we can't bind clock with regmap, then explicitly enable
clock when using.

Signed-off-by: Shengjiu Wang <shengjiu.wang@nxp.com>
Reviewed-by: Viorel Suman <viorel.suman@nxp.com>