RDMA/ocrdma: Support RoCE-v2 in the RC path

This patch implements following changes to support RoCE-v2
in the RC path:

* Get the GID-type for a given sgid.
* Based on the GID-type get IPv4/IPv6 L3-address
  and give those to underlying device.
* Resolve and provide network header type to device.

Signed-off-by: Somnath Kotur <somnath.kotur@avagotech.com>
Signed-off-by: Devesh Sharma <devesh.sharma@avagotech.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>