net/mlx5: Unregister traps on driver unload flow

Before this patch, devlink traps are registered only on full driver
probe and unregistered on driver removal. As devlink traps are not
usable once driver functionality is unloaded, it should be unrgeistered
also on flows that unload the driver and then registered when loaded
back, e.g. devlink reload flow.

Signed-off-by: Moshe Shemesh <moshe@nvidia.com>
Reviewed-by: Aya Levin <ayal@nvidia.com>
Signed-off-by: Saeed Mahameed <saeedm@nvidia.com>