hvf: arm: Implement -cpu host

Now that we have working system register sync, we push more target CPU
properties into the virtual machine. That might be useful in some
situations, but is not the typical case that users want.

So let's add a -cpu host option that allows them to explicitly pass all
CPU capabilities of their host CPU into the guest.

Signed-off-by: Alexander Graf <agraf@csgraf.de>
Acked-by: Roman Bolshakov <r.bolshakov@yadro.com>
Reviewed-by: Sergio Lopez <slp@redhat.com>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Message-id: 20210916155404.86958-7-agraf@csgraf.de
[PMM: drop unnecessary #include line from .h file]
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>

target/arm/hvf_arm.h

@@ -0,0 +1,18 @@
+/*
+ * QEMU Hypervisor.framework (HVF) support -- ARM specifics
+ *
+ * Copyright (c) 2021 Alexander Graf
+ *
+ * This work is licensed under the terms of the GNU GPL, version 2 or later.
+ * See the COPYING file in the top-level directory.
+ *
+ */
+
+#ifndef QEMU_HVF_ARM_H
+#define QEMU_HVF_ARM_H
+
+#include "cpu.h"
+
+void hvf_arm_set_cpu_features_from_host(struct ARMCPU *cpu);
+
+#endif