kvm: Handle exit reason KVM_EXIT_SYSTEM_EVENT

kvm: Handle exit reason KVM_EXIT_SYSTEM_EVENT

In-kernel PSCI v0.2 emulation of KVM ARM/ARM64 forwards SYSTEM_OFF
and SYSTEM_RESET function calls to QEMU using KVM_EXIT_SYSTEM_EVENT
exit reason.

This patch updates kvm_cpu_exec() to handle KVM_SYSTEM_EVENT_SHUTDOWN
and KVM_SYSTEM_EVENT_RESET system-level events from QEMU-side.

Signed-off-by: Pranavkumar Sawargaonkar <pranavkumar@linaro.org>
Signed-off-by: Anup Patel <anup.patel@linaro.org>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Message-id: 1402901605-24551-4-git-send-email-pranavkumar@linaro.org
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>