ixgbe: Delete a bunch of dead code

All of the code involved with returning the supported physical
layer is actually unused, so delete it.

Signed-off-by: Mark Rustad <mark.d.rustad@intel.com>
Tested-by: Phil Schmitt <phillip.j.schmitt@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>

diff --cc drivers/net/ethernet/intel/ixgbe/ixgbe_82598.c
Simple merge

diff --cc drivers/net/ethernet/intel/ixgbe/ixgbe_82599.c
Simple merge

diff --cc drivers/net/ethernet/intel/ixgbe/ixgbe_type.h
Simple merge

diff --cc drivers/net/ethernet/intel/ixgbe/ixgbe_x540.c
Simple merge