net/mlx5: Unload device upon firmware fatal error

When fw_fatal reporter reports an error, the firmware in not responding.
Unload the device to ensure that the driver closes all its resources,
even if recovery is not due (user disabled auto-recovery or reporter is
in grace period). On successful recovery the device is loaded back up.

Fixes: b3bd076f ("net/mlx5: Report devlink health on FW fatal issues")
Signed-off-by: Aya Levin <ayal@nvidia.com>
Reviewed-by: Moshe Shemesh <moshe@nvidia.com>
Signed-off-by: Saeed Mahameed <saeedm@nvidia.com>