IB/core: Add Scatter FCS create flag

Raw Packet QPs that were created with Scatter FCS flag, will scatter
the FCS into the receive buffers.

Signed-off-by: Majd Dibbiny <majd@mellanox.com>
Signed-off-by: Matan Barak <matanb@mellanox.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>