igc: Remove unused CTRL_EXT_LINK_MODE_MASK

We support only copper mode
Not applicable for i225 parts
Signed-off-by: NSasha Neftin <sasha.neftin@intel.com>
Tested-by: NAaron Brown <aaron.f.brown@intel.com>
Signed-off-by: NJeff Kirsher <jeffrey.t.kirsher@intel.com>

drivers/net/ethernet/intel/igc/igc_defines.h

@@ -44,9 +44,6 @@
 /* Wake Up Packet Memory stores the first 128 bytes of the wake up packet */
 #define IGC_WUPM_BYTES	128
 
-/* Physical Func Reset Done Indication */
-#define IGC_CTRL_EXT_LINK_MODE_MASK	0x00C00000
-
 /* Loop limit on how long we wait for auto-negotiation to complete */
 #define COPPER_LINK_UP_LIMIT		10
 #define PHY_AUTO_NEG_LIMIT		45