Introduce kvm_arch_irqchip_create an arch-specific hook in preparation
for architecture-specific use of the device control API to create IRQ
chips.

Following patches will implement the ARM irqchip create method to prefer
the device control API over the older KVM_CREATE_IRQCHIP API.
Reviewed-by: NPeter Maydell <peter.maydell@linaro.org>
Signed-off-by: NChristoffer Dall <christoffer.dall@linaro.org>
Message-id: 1392687720-26806-3-git-send-email-christoffer.dall@linaro.org
Signed-off-by: NPeter Maydell <peter.maydell@linaro.org>