net/mlx5e: Re-work TIS creation functions

Let the EN TIS creation function (mlx5e_create_tis) be responsible
for applying common mdev related fields.
Other specific fields must be set by the caller and passed within
the inbox.

Signed-off-by: Tariq Toukan <tariqt@mellanox.com>
Reviewed-by: Boris Pismenny <borisp@mellanox.com>
Signed-off-by: Saeed Mahameed <saeedm@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>