ASoC: mt6359: reduce log verbosity for optional DT properties

DT properties "dmic-mode" and "mic-type-X" are optional.  Reduces the
log verbosity and changes the message a bit to avoid misleading.

Signed-off-by: Tzung-Bi Shih <tzungbi@google.com>
Link: https://lore.kernel.org/r/20210202033557.1621029-1-tzungbi@google.com


Signed-off-by: Mark Brown <broonie@kernel.org>