When the DMIC_ENA bit is set the analogue inputs are disconnected from
the digital core of the chip, in favour of the digital microphones.
Currently the driver will always enable DMIC_ENA whilst the GPIOs are
configured for the DMIC function, this means the user can't currently
use both the analog inputs and the digital inputs in one system.

Add an additional DAPM mutex that allows switching between analog and
digital inputs into the digital core.
Reported-by: NMartin Kepplinger <martin.kepplinger@puri.sm>
Signed-off-by: NCharles Keepax <ckeepax@opensource.cirrus.com>
Reported-and-tested-by: NMartin Kepplinger <martin.kepplinger@puri.sm>
Link: https://lore.kernel.org/r/20220202164545.30457-1-ckeepax@opensource.cirrus.comSigned-off-by: NMark Brown <broonie@kernel.org>