ath9k: Update copyright in all the files

How time flies.

Signed-off-by: Sujith <Sujith.Manoharan@atheros.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
diff --git a/drivers/net/wireless/ath9k/ahb.c b/drivers/net/wireless/ath9k/ahb.c
index 00cc7bb..0e65c51 100644
--- a/drivers/net/wireless/ath9k/ahb.c
+++ b/drivers/net/wireless/ath9k/ahb.c
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2008 Atheros Communications Inc.
+ * Copyright (c) 2008-2009 Atheros Communications Inc.
  * Copyright (c) 2009 Gabor Juhos <juhosg@openwrt.org>
  * Copyright (c) 2009 Imre Kaloz <kaloz@openwrt.org>
  *