ath9k_hw: use register name in place of magic value

Signed-off-by: NAlex Hacker <hacker@epn.ru>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

drivers/net/wireless/ath/ath9k/ar9003_eeprom.c

@@ -4188,7 +4188,7 @@ static int ar9003_hw_tx_power_regwrite(struct ath_hw *ah, u8 * pPwrArray)
         /* Write the power for duplicated frames - HT40 */
 
         /* dup40_cck (LSB), dup40_ofdm, ext20_cck, ext20_ofdm (MSB) */
-	REG_WRITE(ah, 0xa3e0,
+	REG_WRITE(ah, AR_PHY_POWER_TX_RATE(8),
 		  POW_SM(pPwrArray[ALL_TARGET_LEGACY_6_24], 24) |
 		  POW_SM(pPwrArray[ALL_TARGET_LEGACY_1L_5L], 16) |
 		  POW_SM(pPwrArray[ALL_TARGET_LEGACY_6_24],  8) |