net/mlx5: DR, Proper handling of unsupported Connect-X6DX SW steering

net/mlx5: DR, Proper handling of unsupported Connect-X6DX SW steering

STEs format for Connect-X5 and Connect-X6DX different. Currently, on
Connext-X6DX the SW steering would break at some point when building STEs
w/o giving a proper error message. Fix this by checking the STE format of
the current device when initializing domain: add mlx5_ifc definitions for
Connect-X6DX SW steering, read FW capability to get the current format
version, and check this version when domain is being created.

Fixes: 19059f2dc873 ("net/mlx5: DR, Add Steering entry (STE) utilities")
Signed-off-by: Yevgeny Kliteynik <kliteyn@nvidia.com>
Signed-off-by: Saeed Mahameed <saeedm@nvidia.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>