RDMA/ocrdma: Export udp encapsulation capability

Add support to read device configuration and initialize port-immutables
to report UDP-Encap flag during port query.

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