sfc: Update copyright banners

Update the dates for files that have been added to in 2012-2013.
Drop the 'Solarstorm' brand name that's still lingering here.

Signed-off-by: Ben Hutchings <bhutchings@solarflare.com>
diff --git a/drivers/net/ethernet/sfc/tx.c b/drivers/net/ethernet/sfc/tx.c
index 82075f9..2ac91c5 100644
--- a/drivers/net/ethernet/sfc/tx.c
+++ b/drivers/net/ethernet/sfc/tx.c
@@ -1,7 +1,7 @@
 /****************************************************************************
- * Driver for Solarflare Solarstorm network controllers and boards
+ * Driver for Solarflare network controllers and boards
  * Copyright 2005-2006 Fen Systems Ltd.
- * Copyright 2005-2010 Solarflare Communications Inc.
+ * Copyright 2005-2013 Solarflare Communications Inc.
  *
  * This program is free software; you can redistribute it and/or modify it
  * under the terms of the GNU General Public License version 2 as published