qedr: Add RoCE driver framework

Adds a skeletal implementation of the qed* RoCE driver -
basically the ability to communicate with the qede driver and
receive notifications from it regarding various init/exit events.

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>