isci: Save the suspension hint for upcoming suspensions.

In the case of a suspend call while in SCI_RNC_POSTING or INVALIDATING
states, the LLHANG detect needed to be saved so the upcoming suspension
would enable it correctly.  The unused suspend callback parameters were
removed.

Signed-off-by: Jeff Skirvin <jeffrey.d.skirvin@intel.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>