Currently when a remote subsystem goes down, remove_subdev will be called from rproc for removing that subsystem from the list, but this could be too late. Register for early SSR notifications for getting notified about before shutdown, so that the glink_send calls to the dead processor will not get blocked. Change-Id: Ief7f90caf69f2855272579bc63140837e0efc447 Signed-off-by: Sarannya S <quic_sarannya@quicinc.com>