doc: fix supported feature table in mlx5 guide

[ upstream commit 5f5b0ac ]

This sets the correct minimal requirements for these features:

- Buffer Split offload is supported/verified on ConnectX-5
- Tx scheduling requires ConnectX-6DX and depends on firmware version

Fixes: cb7b0c2 ("doc: update hardware offloads support in mlx5 guide")

Signed-off-by: Viacheslav Ovsiienko <viacheslavo@nvidia.com>
Reviewed-by: Asaf Penso <asafp@nvidia.com>

doc/guides/nics/mlx5.rst

@@ -1385,7 +1385,8 @@ Supported hardware offloads
    Rx timestamp   17.11  4.14    16     4.2-1 12.21.1000 ConnectX-4
    TSO            17.11  4.14    16     4.2-1 12.21.1000 ConnectX-4
    LRO            19.08  N/A     N/A    4.6-4 16.25.6406 ConnectX-5
-   Buffer Split   20.11  N/A     N/A    5.1-2 22.28.2006 ConnectX-6 Dx
+   Tx scheduling  20.08  N/A     N/A    5.1-2 22.28.2006 ConnectX-6 Dx
+   Buffer Split   20.11  N/A     N/A    5.1-2 16.28.2006 ConnectX-5
    ============== ===== ===== ========= ===== ========== =============
 
 .. table:: Minimal SW/HW versions for rte_flow offloads