igb: add completion timeout workaround for 82575/82576

The 82575 and 82576 hardware can both experience data corruption issues if
a pci-e completion arrives after the timeout value.  In order to avoid this
we need to increase the timeout value while pci-e master is disabled.

Signed-off-by: Alexander Duyck <alexander.h.duyck@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/drivers/net/igb/e1000_hw.h b/drivers/net/igb/e1000_hw.h
index f096ddd..eb41f3b 100644
--- a/drivers/net/igb/e1000_hw.h
+++ b/drivers/net/igb/e1000_hw.h
@@ -494,5 +494,7 @@
 #else
 #define hw_dbg(format, arg...)
 #endif
-
 #endif
+/* These functions must be implemented by drivers */
+s32  igb_read_pcie_cap_reg(struct e1000_hw *hw, u32 reg, u16 *value);
+s32  igb_write_pcie_cap_reg(struct e1000_hw *hw, u32 reg, u16 *value);