Drivers: hv: vmbus: Implement the protocol for tearing down vmbus state

Implement the protocol for tearing down the monitor state established with
the host.

Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Tested-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
diff --git a/include/linux/hyperv.h b/include/linux/hyperv.h
index e29ccdd..ea93486 100644
--- a/include/linux/hyperv.h
+++ b/include/linux/hyperv.h
@@ -389,6 +389,7 @@
 	CHANNELMSG_INITIATE_CONTACT		= 14,
 	CHANNELMSG_VERSION_RESPONSE		= 15,
 	CHANNELMSG_UNLOAD			= 16,
+	CHANNELMSG_UNLOAD_RESPONSE		= 17,
 	CHANNELMSG_COUNT
 };