irqchip/sl28cpld: 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>
Reviewed-by: Michael Walle <michael@walle.cc>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20221112152701.41990-1-aidanmacdonald.0x0@gmail.com

drivers/irqchip/irq-sl28cpld.c

@@ -65,8 +65,7 @@ static int sl28cpld_intc_probe(struct platform_device *pdev)
 	irqchip->chip.num_irqs = ARRAY_SIZE(sl28cpld_irqs);
 	irqchip->chip.num_regs = 1;
 	irqchip->chip.status_base = base + INTC_IP;
-	irqchip->chip.mask_base = base + INTC_IE;
-	irqchip->chip.mask_invert = true;
+	irqchip->chip.unmask_base = base + INTC_IE;
 	irqchip->chip.ack_base = base + INTC_IP;
 
 	return devm_regmap_add_irq_chip_fwnode(dev, dev_fwnode(dev),