Under virtualization guest needs to receive notification from host to
perform reset in some cases. Add nv mailbox irq in soc21.
Signed-off-by: NYuBiao Wang <YuBiao.Wang@amd.com>
Reviewed-by: NHawking Zhang <Hawking.Zhang@amd.com>
Signed-off-by: NAlex Deucher <alexander.deucher@amd.com>