tg3: Move tg3_init_link_config to tg3_phy_probe

This patch moves the function that initializes the link configuration
closer to the place where the rest of the phy code is initialized.

Signed-off-by: Matt Carlson <mcarlson@broadcom.com>
Reviewed-by: Michael Chan <mchan@broadcom.com>
Signed-off-by: David S. Miller <davem@davemloft.net>