mfd: 88pm800: Replace irqchip mask_invert with unmask_base

Remove use of the deprecated mask_invert flag. Inverted mask
registers (where a '1' bit enables an IRQ) can be described more
directly as an unmask register.
Signed-off-by: Aidan MacDonald <aidanmacdonald.0x0@gmail.com>
Signed-off-by: Lee Jones <lee@kernel.org>
Link: https://lore.kernel.org/r/20221112151835.39059-2-aidanmacdonald.0x0@gmail.com

drivers/mfd/88pm800.c

@@ -398,9 +398,8 @@ static struct regmap_irq_chip pm800_irq_chip = {
 
 	.num_regs = 4,
 	.status_base = PM800_INT_STATUS1,
-	.mask_base = PM800_INT_ENA_1,
+	.unmask_base = PM800_INT_ENA_1,
 	.ack_base = PM800_INT_STATUS1,
-	.mask_invert = 1,
 };
 
 static int pm800_pages_init(struct pm80x_chip *chip)