IB/mlx5: Add block multicast loopback support

Add support for the block multicast loopback QP creation flag along
the proper firmware API for that.

Signed-off-by: Eli Cohen <eli@mellanox.com>
Signed-off-by: Or Gerlitz <ogerlitz@mellanox.com>
Signed-off-by: Roland Dreier <roland@purestorage.com>
diff --git a/include/linux/mlx5/qp.h b/include/linux/mlx5/qp.h
index f829ad8..9709b30 100644
--- a/include/linux/mlx5/qp.h
+++ b/include/linux/mlx5/qp.h
@@ -146,6 +146,7 @@
 
 enum {
 	MLX5_QP_LAT_SENSITIVE	= 1 << 28,
+	MLX5_QP_BLOCK_MCAST	= 1 << 30,
 	MLX5_QP_ENABLE_SIG	= 1 << 31,
 };