cxgb3 - Tighten xgmac workaround

Run the watchdog task when the link is up.
Flush the XGMAC Tx FIFO when the link drops.

Also remove a statistics update that should have gone
in the previous modification of xgmac.c.

Signed-off-by: Divy Le Ray <divy@chelsio.com>
Signed-off-by: Jeff Garzik <jeff@garzik.org>
diff --git a/drivers/net/cxgb3/regs.h b/drivers/net/cxgb3/regs.h
index b38629a..f8be41c 100644
--- a/drivers/net/cxgb3/regs.h
+++ b/drivers/net/cxgb3/regs.h
@@ -1940,6 +1940,10 @@
 
 #define V_TXFIFOTHRESH(x) ((x) << S_TXFIFOTHRESH)
 
+#define S_ENDROPPKT    21
+#define V_ENDROPPKT(x) ((x) << S_ENDROPPKT)
+#define F_ENDROPPKT    V_ENDROPPKT(1U)
+
 #define A_XGM_SERDES_CTRL 0x890
 #define A_XGM_SERDES_CTRL0 0x8e0