ASoC: wcd9320: release codec mutex before calling dapm function

DAPM calls will internally acquire soc_card class locks for its
operations. Therefore, release codec->mutex before calling into
snd_soc_dapm_mux_update_power and snd_soc_dapm_mixer_update_power.
This will help avoid deadlock inside those functions.

CRs-fixed: 612080
Change-Id: I6bb943389240b67e1847bc533ac56fdd20799bce
Signed-off-by: Banajit Goswami <bgoswami@codeaurora.org>