tg3: Add external loopback support to selftest

This patch adds external loopback support to tg3's ethtool selftest.

Signed-off-by: Matt Carlson <mcarlson@broadcom.com>
Reviewed-by: Michael Chan <mchan@broadcom.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/drivers/net/ethernet/broadcom/tg3.h b/drivers/net/ethernet/broadcom/tg3.h
index 2ea456d..d2976f3 100644
--- a/drivers/net/ethernet/broadcom/tg3.h
+++ b/drivers/net/ethernet/broadcom/tg3.h
@@ -2197,6 +2197,7 @@
 #define MII_TG3_AUXCTL_ACTL_TX_6DB	0x0400
 #define MII_TG3_AUXCTL_ACTL_SMDSP_ENA	0x0800
 #define MII_TG3_AUXCTL_ACTL_EXTPKTLEN	0x4000
+#define MII_TG3_AUXCTL_ACTL_EXTLOOPBK	0x8000
 
 #define MII_TG3_AUXCTL_SHDWSEL_PWRCTL	0x0002
 #define MII_TG3_AUXCTL_PCTL_WOL_EN	0x0008
@@ -2262,6 +2263,8 @@
 
 /* Fast Ethernet Tranceiver definitions */
 #define MII_TG3_FET_PTEST		0x17
+#define  MII_TG3_FET_PTEST_TRIM_SEL	0x0010
+#define  MII_TG3_FET_PTEST_TRIM_2	0x0002
 #define  MII_TG3_FET_PTEST_FRC_TX_LINK	0x1000
 #define  MII_TG3_FET_PTEST_FRC_TX_LOCK	0x0800