[SCSI] isci: kill iphy->isci_port lookups

This field is a holdover from the OS abstraction conversion.  The stable
phy to port lookups are done via iphy->ownining_port under scic_lock.
After this conversion to use port->lldd_port the only volatile lookup is
the initial lookup in isci_port_formed().  After that point any lookup
via a successfully notified domain_device is guaranteed to be valid
until the domain_device is destroyed.

Delete ->start_complete as it is only set once and is set as a
consequence of the port going link up, by definition of getting a port
formed event the port is "ready".

While we are correcting port lookups also move the asd_sas_port table
out from under the isci_port.  This is to preclude any temptation to use
container_of() to convert an asd_sas_port to an isci_port, the
association is dynamic and under libsas control.

Tested-by: Maciej Trela <maciej.trela@intel.com>
[dmilburn@redhat.com: fix i686 compile error]
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>