RDMA/bnxt_re: Add bnxt_re RoCE driver

RDMA/bnxt_re: Add bnxt_re RoCE driver

This patch introduces the RoCE driver for the Broadcom
NetXtreme-E 10/25/40/50G RoCE HCAs.

The RoCE driver is a two part driver that relies on the parent
bnxt_en NIC driver to operate.  The changes needed in the bnxt_en
driver have already been incorporated via Dave Miller's net tree
into the mainline kernel.

The vendor official git repository for this driver is available
on github as:
https://github.com/Broadcom/linux-rdma-nxt/

Signed-off-by: Eddie Wai <eddie.wai@broadcom.com>
Signed-off-by: Devesh Sharma <devesh.sharma@broadcom.com>
Signed-off-by: Somnath Kotur <somnath.kotur@broadcom.com>
Signed-off-by: Sriharsha Basavapatna <sriharsha.basavapatna@broadcom.com>
Signed-off-by: Selvin Xavier <selvin.xavier@broadcom.com>
Reviewed-by: Leon Romanovsky <leonro@mellanox.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>