IB/iser: Introduce iser_reg_ops

Move all the per-device function pointers to an easy
extensible iser_reg_ops structure that contains all
the iser registration operations.

Signed-off-by: Sagi Grimberg <sagig@mellanox.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>

diff --cc drivers/infiniband/ulp/iser/iscsi_iser.h
Simple merge

diff --cc drivers/infiniband/ulp/iser/iser_initiator.c
Simple merge

diff --cc drivers/infiniband/ulp/iser/iser_memory.c
Simple merge

diff --cc drivers/infiniband/ulp/iser/iser_verbs.c
Simple merge