RDMA: Introduce ib_port_phys_state enum

In order to improve readability, add ib_port_phys_state enum to replace
the use of magic numbers.

Signed-off-by: Kamal Heib <kamalheib1@gmail.com>
Reviewed-by: Andrew Boyer <aboyer@tobark.org>
Acked-by: Michal Kalderon <michal.kalderon@marvell.com>
Acked-by: Bernard Metzler <bmt@zurich.ibm.com>
Link: https://lore.kernel.org/r/20190807103138.17219-2-kamalheib1@gmail.com


Signed-off-by: Doug Ledford <dledford@redhat.com>