net/mlx5: Start health poll at earlier stage of driver load

Start health poll at earlier stage, so if fw fatal issue occurred before
or during initialization commands such as init_hca or set_hca_cap the
poll health can detect and indicate that the driver is already in error
state.

Signed-off-by: Moshe Shemesh <moshe@nvidia.com>
Signed-off-by: Saeed Mahameed <saeedm@nvidia.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>