ASoC: cs42l43: Add missing statics for hp_ilimit functions

Fixes: bbbc18d8

 ("ASoC: cs42l43: Allow HP amp to cool off after current limit")
Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Charles Keepax <ckeepax@opensource.cirrus.com>
Link: https://msgid.link/r/20231212104149.2388753-1-ckeepax@opensource.cirrus.com


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