ASoC: max9867: don't use regmap defaults

MAX9867 codec doesn't have reset pin, so the registers don't
have default values in the case of reboot without powering off.
Remove the reg_defaults struct and let the regmap read initial
state of the registers at startup instead of taking them from
reg_defaults struct.

Signed-off-by: Pavel Dobias <dobias@2n.cz>
Link: https://lore.kernel.org/r/20200520071904.15801-2-dobias@2n.cz


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