piix4: Add the Reset Control Register

piix4: Add the Reset Control Register

The RCR I/O port (0xcf9) is used to generate a hard reset or a soft reset.

Acked-by: Michael S. Tsirkin <mst@redhat.com>
Acked-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Hervé Poussineau <hpoussin@reactos.org>
Message-Id: <20171216090228.28505-7-hpoussin@reactos.org>
Reviewed-by: Aleksandar Markovic <amarkovic@wavecomp.com>
Reviewed-by: Li Qiang <liq3ea@gmail.com>
[PMD: rebased, updated includes]
Signed-off-by: Philippe Mathieu-Daudé <philmd@redhat.com>