ASoC: cs35l41: Correct handling of some registers in the cache

It makes no sense to cache the test/user key registers, since they
require values written at specific times, mark them volatile. It is
probably best if they can't be accessed from user-space either, so
mark them precious as well.

The interrupt force, edge, polarity and debounce are all settings
applied to the IRQ rather than status bits and as such should not be
volatile.

The OTP trim values will require re-application in the event of a
cache sync and as such should not be volatile. The OTPID however
should be volatile.

The DSP scratch registers are used to read back an error/debug code
from the DSP on shutdown, as such these should be marked volatile.

Finally, add some missing defaults, add TST_FS_MON0, and allow the
DSP core control register to be cached.

Signed-off-by: Charles Keepax <ckeepax@opensource.cirrus.com>
Link: https://lore.kernel.org/r/20220105113026.18955-5-ckeepax@opensource.cirrus.com
Signed-off-by: Mark Brown <broonie@kernel.org>