ixgbe: minor sparse fixes

Make strings const if possible, and fix includes so forward definitions
are seen.

Signed-off-by: Stephen Hemminger <shemminger@linux-foundation.org>
Signed-off-by: Auke Kok <auke-jan.h.kok@intel.com>
Signed-off-by: Jeff Garzik <jeff@garzik.org>
diff --git a/drivers/net/ixgbe/ixgbe_main.c b/drivers/net/ixgbe/ixgbe_main.c
index b75f1c6..00bc525 100644
--- a/drivers/net/ixgbe/ixgbe_main.c
+++ b/drivers/net/ixgbe/ixgbe_main.c
@@ -45,12 +45,13 @@
 #include "ixgbe_common.h"
 
 char ixgbe_driver_name[] = "ixgbe";
-static char ixgbe_driver_string[] =
-			"Intel(R) 10 Gigabit PCI Express Network Driver";
+static const char ixgbe_driver_string[] =
+	"Intel(R) 10 Gigabit PCI Express Network Driver";
 
 #define DRV_VERSION "1.1.18"
-char ixgbe_driver_version[] = DRV_VERSION;
-static char ixgbe_copyright[] = "Copyright (c) 1999-2007 Intel Corporation.";
+const char ixgbe_driver_version[] = DRV_VERSION;
+static const char ixgbe_copyright[] =
+	 "Copyright (c) 1999-2007 Intel Corporation.";
 
 static const struct ixgbe_info *ixgbe_info_tbl[] = {
 	[board_82598AF]			= &ixgbe_82598AF_info,