qedr: Add support for RoCE HW init

Allocate and setup RoCE resources, interrupts and completion queues.
Adds device attributes.

Signed-off-by: Rajesh Borundia <rajesh.borundia@cavium.com>
Signed-off-by: Ram Amrani <Ram.Amrani@cavium.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>