net/mlx5: Bridge, fix ageing time

Ageing time is not converted from clock_t to jiffies which results
incorrect ageing timeout calculation in workqueue update task. Fix it by
applying clock_t_to_jiffies() to provided value.

Fixes: c636a0f0 ("net/mlx5: Bridge, dynamic entry ageing")
Signed-off-by: Vlad Buslov <vladbu@nvidia.com>
Signed-off-by: Saeed Mahameed <saeedm@nvidia.com>