ixgbe: add ethtool counters for OS2BMC

OS2BMC registers are available for X540.
This patch adds ethtool counters based on those registers.

Signed-off-by: Emil Tantilov <emil.s.tantilov@intel.com>
Tested-by: Evan Swanson <evan.swanson@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
diff --git a/drivers/net/ixgbe/ixgbe_main.c b/drivers/net/ixgbe/ixgbe_main.c
index 56cc9a1..a3e384b 100644
--- a/drivers/net/ixgbe/ixgbe_main.c
+++ b/drivers/net/ixgbe/ixgbe_main.c
@@ -5912,8 +5912,13 @@
 		hwstats->gotc += IXGBE_READ_REG(hw, IXGBE_GOTCH);
 		hwstats->tor += IXGBE_READ_REG(hw, IXGBE_TORH);
 		break;
-	case ixgbe_mac_82599EB:
 	case ixgbe_mac_X540:
+		/* OS2BMC stats are X540 only*/
+		hwstats->o2bgptc += IXGBE_READ_REG(hw, IXGBE_O2BGPTC);
+		hwstats->o2bspc += IXGBE_READ_REG(hw, IXGBE_O2BSPC);
+		hwstats->b2ospc += IXGBE_READ_REG(hw, IXGBE_B2OSPC);
+		hwstats->b2ogprc += IXGBE_READ_REG(hw, IXGBE_B2OGPRC);
+	case ixgbe_mac_82599EB:
 		hwstats->gorc += IXGBE_READ_REG(hw, IXGBE_GORCL);
 		IXGBE_READ_REG(hw, IXGBE_GORCH); /* to clear */
 		hwstats->gotc += IXGBE_READ_REG(hw, IXGBE_GOTCL);