mfd: cs42l43: Remove IRQ masking in suspend

Now the individual child drivers mask their own IRQs there is no need
for the MFD code to do so anymore.

Signed-off-by: Charles Keepax <ckeepax@opensource.cirrus.com>
Link: https://lore.kernel.org/r/20250903094549.271068-7-ckeepax@opensource.cirrus.com


Signed-off-by: Lee Jones <lee@kernel.org>