KVM: arm/arm64: remove coarse grain dist locking at kvm_vgic_sync_hwstate

To prepare for irqfd addition, coarse grain locking is removed at
kvm_vgic_sync_hwstate level and finer grain locking is introduced in
vgic_process_maintenance only.

Signed-off-by: Eric Auger <eric.auger@linaro.org>
Acked-by: Christoffer Dall <christoffer.dall@linaro.org>
Acked-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>