ASoC: cs42l43: Add missing static from runtime PM ops

Fixes: 2b59332e

 ("ASoC: cs42l43: Use new-style PM runtime macros")
Reported-by: kernel test robot <lkp@intel.com>
Closes: https://lore.kernel.org/oe-kbuild-all/202311091824.5z6PROGZ-lkp@intel.com/
Signed-off-by: Charles Keepax <ckeepax@opensource.cirrus.com>
Link: https://lore.kernel.org/r/20231113151429.1554139-1-ckeepax@opensource.cirrus.com
Signed-off-by: Mark Brown <broonie@kernel.org>