A substate is just a state, so uplevel the smp and stp device substates.
Three tricks at work here:

1/ scic_sds_remote_device_ready_state_enter: needs to know the the device type
   so it can immediately transition to a stp or smp ready substate.

2/ scic_sds_remote_device_ready_state_exit: needs to know the device type. In
   the ssp case the device is no longer ready, in the stp, and smp case we have
   simply exited to a ready "substate".

3/ scic_sds_remote_device_resume_complete_handler: The one location
   where we directly check the current state against
   SCI_BASE_REMOTE_DEVICE_STATE_READY needed to comprehend the possible ready
   substates.
Reported-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>