qedr: Add user space support for SRQ

This patch adds support for SRQ's created in user space and update
qedr_affiliated_event to deal with general SRQ events.

Signed-off-by: Michal Kalderon <michal.kalderon@cavium.com>
Signed-off-by: Yuval Bason <yuval.bason@cavium.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>