[TG3]: Clear GPIO mask before storing.

The GPIO settings may change during reset and so the stored values in
tp->grc_local_ctrl should be cleared first.

Signed-off-by: Gary Zambrano <zambrano@broadcom.com>
Signed-off-by: Michael Chan <mchan@broadcom.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/drivers/net/tg3.c b/drivers/net/tg3.c
index c01bd86..00027a1 100644
--- a/drivers/net/tg3.c
+++ b/drivers/net/tg3.c
@@ -6454,6 +6454,7 @@
 		if (GET_ASIC_REV(tp->pci_chip_rev_id) == ASIC_REV_5755)
 			gpio_mask |= GRC_LCLCTRL_GPIO_UART_SEL;
 
+		tp->grc_local_ctrl &= ~gpio_mask;
 		tp->grc_local_ctrl |= tr32(GRC_LOCAL_CTRL) & gpio_mask;
 
 		/* GPIO1 must be driven high for eeprom write protect */