tg3: Remove unused link config code

tg3: Remove unused link config code

When tg3 devices are shutdown, the driver uses the
TG3_PHYFLG_IS_LOW_POWER flag to enable a static phy configuration.
Any attempt to use the link configuration variables is dead code.  This
patch removes such code.

(cherry picked from commit 2855b9fe416e55d01a1946b142d87abd4cceb6ea)
Signed-off-by: Matt Carlson <mcarlson@broadcom.com>
Reviewed-by: Michael Chan <mchan@broadcom.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Joe Jin <joe.jin@oracle.com>