igb: Enable EEE LP advertisement

On EEE-capable devices, query the PHY to determine what the link partner is
advertising.

Signed-off-by: Matthew Vick <matthew.vick@intel.com>
Tested-by: Aaron Brown <aaron.f.brown@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
diff --git a/drivers/net/ethernet/intel/igb/e1000_regs.h b/drivers/net/ethernet/intel/igb/e1000_regs.h
index 971b638..bdfc040 100644
--- a/drivers/net/ethernet/intel/igb/e1000_regs.h
+++ b/drivers/net/ethernet/intel/igb/e1000_regs.h
@@ -365,6 +365,10 @@
 #define E1000_IPCNFG	0x0E38 /* Internal PHY Configuration */
 #define E1000_EEER	0x0E30 /* Energy Efficient Ethernet */
 #define E1000_EEE_SU	0X0E34 /* EEE Setup */
+#define E1000_EMIADD	0x10   /* Extended Memory Indirect Address */
+#define E1000_EMIDATA	0x11   /* Extended Memory Indirect Data */
+#define E1000_MMDAC	13     /* MMD Access Control */
+#define E1000_MMDAAD	14     /* MMD Access Address/Data */
 
 /* Thermal Sensor Register */
 #define E1000_THSTAT	0x08110 /* Thermal Sensor Status */