ASoC: fsl_sai: Add missing registers to cache default

ASoC: fsl_sai: Add missing registers to cache default

Drivers does cache sync during runtime resume, setting all writable
registers. Not all writable registers are set in cache default, resulting
in the erorr message:
  fsl-sai 30c30000.sai: using zero-initialized flat cache, this may cause
  unexpected behavior

Fix this by adding missing writable register defaults.

Signed-off-by: Alexander Stein <alexander.stein@ew.tq-group.com>
Link: https://patch.msgid.link/20251216102246.676181-1-alexander.stein@ew.tq-group.com
Signed-off-by: Mark Brown <broonie@kernel.org>