KVM: arm/arm64: vgic: streamline vgic_update_irq_pending() interface

We actually don't use the irq_phys_map parameter in
vgic_update_irq_pending(), so let's just remove it.

Signed-off-by: Andre Przywara <andre.przywara@arm.com>
Reviewed-by: Eric Auger <eric.auger@linaro.org>
Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org>