PCI: aardvark: Remove irq_mask_ack() callback for INTx interrupts

Callback for irq_mask_ack() is the same as for irq_mask(). As there is no
special handling for irq_ack(), there is no need to define irq_mask_ack()
too.

Link: https://lore.kernel.org/r/20220110015018.26359-20-kabel@kernel.org


Signed-off-by: Pali Rohár <pali@kernel.org>
Signed-off-by: Marek Behún <kabel@kernel.org>
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Acked-by: Marc Zyngier <maz@kernel.org>