mlxsw: core: Re-order initialization sequence

The driver core first registers with the hwmon and thermal subsystems
and only then proceeds to initialize the switch driver (e.g.,
mlxsw_spectrum). It is only during the last stage that the current
firmware version is validated and a newer one flashed, if necessary.

The above means that if a new firmware feature is utilized by the
hwmon/thermal code, the driver will not be able to load.

Solve this by re-ordering initializing the switch driver before
registering with the hwmon and thermal subsystems.

Signed-off-by: Ido Schimmel <idosch@mellanox.com>
Reported-by: Shalom Toledo <shalomt@mellanox.com>
Acked-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>