RDMA/vmw_pvrdma: Fix network_hdr_type reported in WC

The PVRDMA device HW interface defines network_hdr_type according to an
old definition of the internal kernel rdma_network_type enum that has
since changed, resulting in the wrong rdma_network_type being reported.

Fix this by explicitly defining the enum used by the PVRDMA device and
adding a function to convert the pvrdma_network_type to rdma_network_type
enum.

Cc: stable@vger.kernel.org # 5.10+
Fixes: 1c15b4f2

 ("RDMA/core: Modify enum ib_gid_type and enum rdma_network_type")
Link: https://lore.kernel.org/r/1611026189-17943-1-git-send-email-bryantan@vmware.com
Reviewed-by: Adit Ranadive <aditr@vmware.com>
Signed-off-by: Bryan Tan <bryantan@vmware.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>