hv: Add reboot shell command

To trigger warm reboot for debugging.

Signed-off-by: Yin Fengwei <fengwei.yin@intel.com>
Acked-by: Eddie Dong <Eddie.dong@intel.com>

hypervisor/arch/x86/debug/reboot.c

@@ -0,0 +1,12 @@
+/*
+ * Copyright (C) <2018> Intel Corporation
+ * SPDX-License-Identifier: BSD-3-Clause
+ */
+#include <acrn_common.h>
+#include <io.h>
+
+int warm_reboot(void)
+{
+	io_write_byte(0x6, 0xcf9);
+	return 0;
+}