net/mlx5e: Use the new TIR API for kTLS

One of the previous commits introduced a dedicated object for a TIR.
kTLS code creates a TIR per connection using the low-level mlx5_core
API. This commit converts it to the new mlx5e_tir API.

Signed-off-by: Maxim Mikityanskiy <maximmi@nvidia.com>
Reviewed-by: Tariq Toukan <tariqt@nvidia.com>
Signed-off-by: Saeed Mahameed <saeedm@nvidia.com>