IB/ehca: Fix AQP0/1 QP number

AQP0/1 should report qp_num={0|1} and the actual QP# should be stored
in struct ehca_qp, not the other way round.

Signed-off-by: Joachim Fenkes <fenkes@de.ibm.com>
Signed-off-by: Roland Dreier <rolandd@cisco.com>