RDMA/ipoib: Add 50Gb and 100Gb link speeds to ethtool

The IBTA specification has new speeds - HDR and NDR, supporting signaling
rate of 50Gb and 100Gb respectively. ethtool support of ipoib driver
translates IB speed to signaling rate. Added translation of HDR and NDR IB
types to rates of 50Gb and 100Gb ethernet speed.

Link: https://lore.kernel.org/r/20201026132904.1338526-1-leon@kernel.org
Signed-off-by: Meir Lichtinger <meirl@mellanox.com>
Signed-off-by: Leon Romanovsky <leonro@mellanox.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>