New capability bit: ipoib_enhanced_offloads, indicates new ability for UD
QP to do RSS and enhanced IPoIB offloads and acceleration.

Add underlay_qpn to the TIS and flow_table objects In order to support
SET_ROOT command, to connect between IPoIB QPs and flow steering tables.
Signed-off-by: NErez Shitrit <erezsh@mellanox.com>
Signed-off-by: NSaeed Mahameed <saeedm@mellanox.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>