qed: Add srq core support for RoCE and iWARP

This patch adds support for configuring SRQ and provides the necessary
APIs for rdma upper layer driver (qedr) to enable the SRQ feature.

Signed-off-by: Michal Kalderon <michal.kalderon@cavium.com>
Signed-off-by: Ariel Elior <ariel.elior@cavium.com>
Signed-off-by: Yuval Bason <yuval.bason@cavium.com>
Signed-off-by: David S. Miller <davem@davemloft.net>