igb: set lan id prior to configuring phy

The igb driver was defaulting to using the lock for pci-e function 0 for
all of the phys due to the fact that the lan id was not being set prior to
initialization.  This change makes it so that the function id is set prior
to checking for the phy id.

Signed-off-by: Alexander Duyck <alexander.h.duyck@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>