net/mlx5e: kTLS, Check ICOSQ WQE size in advance

Instead of WARNing in runtime when TLS offload WQEs posted to ICOSQ are
over the hardware limit, check their size before enabling TLS RX
offload, and block the offload if the condition fails. It also allows to
drop a u16 field from struct mlx5e_icosq.

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