RDMA/mlx5: Remove ECE limitation from the RAW_PACKET QPs

Like any other QP type, rely on FW for the RAW_PACKET QPs to decide if ECE
is supported or not. This fixes an inability to create RAW_PACKET QPs with
latest rdma-core with the ECE support.

Fixes: e383085c

 ("RDMA/mlx5: Set ECE options during QP create")
Link: https://lore.kernel.org/r/20200618112507.3453496-2-leon@kernel.org
Signed-off-by: Leon Romanovsky <leonro@mellanox.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>