hw/arm/virt: Wire VIRQ, VFIQ, maintenance irq lines from GIC to CPU

Wire the new VIRQ, VFIQ and maintenance interrupt lines from the
GIC to each CPU.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Edgar E. Iglesias <edgar.iglesias@xilinx.com>
Message-id: 1483977924-14522-5-git-send-email-peter.maydell@linaro.org