RDS: Base init_depth and responder_resources on hw values

Instead of using a constant for initiator_depth and
responder_resources, read the per-QP values when the
device is enumerated, and then use these values when creating
the connection.

Signed-off-by: Andy Grover <andy.grover@oracle.com>

diff --cc net/rds/ib.c
Simple merge

diff --cc net/rds/ib.h
Simple merge

diff --cc net/rds/ib_cm.c
Simple merge

diff --cc net/rds/rdma.c
Simple merge