Revert "docs/specs/pvpanic: mark shutdown event as not implemented"

The missing functionality has been implemented now.

This reverts commit e739d1935c461d0668057e9dbba9d06f728d29ec.

Signed-off-by: Thomas Weißschuh <thomas@t-8ch.de>
Message-Id: <20240527-pvpanic-shutdown-v8-8-5a28ec02558b@t-8ch.de>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>

docs/specs/pvpanic.rst

@@ -29,7 +29,7 @@ bit 1
   a guest panic has happened and will be handled by the guest;
   the host should record it or report it, but should not affect
   the execution of the guest.
-bit 2 (to be implemented)
+bit 2
   a regular guest shutdown has happened and should be processed by the host
 
 PCI Interface