MLK-21480: ASoC: wm8962: add constrain for configure bclk

MLK-21480: ASoC: wm8962: add constrain for configure bclk

There is error log when suspend & resume

wm8962 3-001a: Failed to read DSPCLK: -1

when suspend the pm_runtime_suspend is called before the
set_bias_level. so in the wm8962_configure_bclk there is
failure when trying to read a volatile register for we have
enabled regcache_cache_only.

To avoid such issue, we can avoid to call set_bias_level
when the level change from SND_SOC_BIAS_ON to
SND_SOC_BIAS_PREPARE, for this flow is for disabling the codec.

Signed-off-by: Shengjiu Wang <shengjiu.wang@nxp.com>