net/mlx5: fix nested flow creation

net/mlx5: fix nested flow creation

If xmedata mode 1 enabled and create a flow with RSS and mark action,
there was an error that rdma-core failed to create RQT due to wrong
queue definition. This was due to mixed flow creation in thread specific
flow workspace.

This patch introduces nested flow workspace(context data), each flow
uses dedicate flow workspace, pop and restore workspace when nested flow
creation done, the original flow with continue with original flow
workspace. The total number of thread specific flow workspace should be
2 due to only one nested flow creation scenario so far.

Fixes: 8bb81f2649b1 ("net/mlx5: use thread specific flow workspace")
Fixes: 3ac3d8234b82 ("net/mlx5: fix index when creating flow")
Cc: stable@dpdk.org
Signed-off-by: Xueming Li <xuemingl@nvidia.com>
Acked-by: Matan Azrad <matan@nvidia.com>