arm64: KVM: Implement vgic-v2 save/restore

Implement the vgic-v2 save restore (mostly) as a direct translation
of the assembly code version.

Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
(cherry picked from commit 06282fd2c2bf61619649a2b13e4a08556598a64c)
Signed-off-by: Alex Shi <alex.shi@linaro.org>
4 files changed