mfd: wcd934x: Convert irq chip to config regs

Type registers are deprecated and will eventually be removed from
regmap-irq. The same functionality can be replicated with config
registers.

Signed-off-by: Aidan MacDonald <aidanmacdonald.0x0@gmail.com>
Signed-off-by: Lee Jones <lee@kernel.org>
Link: https://lore.kernel.org/r/20221112151835.39059-19-aidanmacdonald.0x0@gmail.com