ath_hw: Use common REG_WRITE parameter order

ath_hw: Use common REG_WRITE parameter order

All defines for REG_WRITE in Atheros wireless drivers use the order "ah",
"register" and "value". hw.c is the only file using the order "ah", "value" and
"register".

drivers/net/wireless/ath/ath9k/hw.h:#define REG_WRITE(_ah, _reg, _val) \
drivers/net/wireless/ath/key.c:#define REG_WRITE(_ah, _reg, _val) (common->ops->write)(_ah, _val, _reg)

This inconsistent definition can easily lead to implementation errors. The
modification doesn't change the behavior of the driver or the generated code.

Signed-off-by: Sven Eckelmann <sven@narfation.org>
Signed-off-by: Simon Wunderlich <siwu@hrz.tu-chemnitz.de>
Acked-by: Luis R. Rodriguez <mcgrof@qca.qualcomm.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>