This class is to be used by both software and KVM implementations of GICv3

Currently it is mostly a placeholder, but in future it is supposed to hold
qemu's representation of GICv3 state, which is necessary for migration.

The interface of this class is fully compatible with GICv2 one. This is
done in order to simplify integration with existing code.
Signed-off-by: NShlomo Pongratz <shlomo.pongratz@huawei.com>
Signed-off-by: NPavel Fedin <p.fedin@samsung.com>
Reviewed-by: NEric Auger <eric.auger@linaro.org>
Tested-by: NAshok kumar <ashoks@broadcom.com>
Reviewed-by: NPeter Maydell <peter.maydell@linaro.org>
Message-id: aff8baaee493cdcab0694b4a1d4dd5ff27c37ed2.1441784344.git.p.fedin@samsung.com
Signed-off-by: NPeter Maydell <peter.maydell@linaro.org>