ath9k: fix compile error in debug.c

drivers/net/wireless/ath9k/debug.c: In function 'read_file_wiphy':
drivers/net/wireless/ath9k/debug.c:377: error: implicit declaration of
function 'put_unaligned_le32'
drivers/net/wireless/ath9k/debug.c:378: error: implicit declaration of
function 'put_unaligned_le16'

Signed-off-by: Gabor Juhos <juhosg@openwrt.org>
Signed-off-by: John W. Linville <linville@tuxdriver.com>