IB/mlx5: Enable QP creation with a given blue flame index

This patch enables QP creation with a given BF index, this allows the
user space driver to share same BF between few QPs or alternatively have
a dedicated BF per QP.

Signed-off-by: Yishai Hadas <yishaih@mellanox.com>
Signed-off-by: Leon Romanovsky <leon@kernel.org>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>

drivers/infiniband/hw/mlx5/mlx5_ib.h

@@ -115,6 +115,7 @@ enum {
 
 enum {
 	MLX5_IB_INVALID_UAR_INDEX	= BIT(31),
+	MLX5_IB_INVALID_BFREG		= BIT(31),
 };
 
 struct mlx5_ib_vma_private_data {