ASoC: fsl_audmix: Don't use devm_regmap_init_mmio_clk

ASoC: fsl_audmix: Don't use devm_regmap_init_mmio_clk

When there is power domain bind with ipg clock,

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

cause the power domain of clock always be enabled after
regmap_init(). which impact the power consumption.

So use devm_regmap_init_mmio instead of
devm_regmap_init_mmio_clk,but explicitly enable
clock when it is used.

Signed-off-by: Shengjiu Wang <shengjiu.wang@nxp.com>
Link: https://lore.kernel.org/r/1616579928-22428-6-git-send-email-shengjiu.wang@nxp.com
Signed-off-by: Mark Brown <broonie@kernel.org>