ath9k: use ath9k_hw_update_regulatory_maxpower in ath9k_hw_def_set_txpower

We have a helper function for updating the max_power_level
value. Use that and remove the duplicated code.
Signed-off-by: NGabor Juhos <juhosg@openwrt.org>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

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

@@ -1263,20 +1263,7 @@ static void ath9k_hw_def_set_txpower(struct ath_hw *ah,
 			regulatory->max_power_level = ratesArray[i];
 	}
 
-	switch(ar5416_get_ntxchains(ah->txchainmask)) {
-	case 1:
-		break;
-	case 2:
-		regulatory->max_power_level += INCREASE_MAXPOW_BY_TWO_CHAIN;
-		break;
-	case 3:
-		regulatory->max_power_level += INCREASE_MAXPOW_BY_THREE_CHAIN;
-		break;
-	default:
-		ath_dbg(ath9k_hw_common(ah), EEPROM,
-			"Invalid chainmask configuration\n");
-		break;
-	}
+	ath9k_hw_update_regulatory_maxpower(ah);
 
 	if (test)
 		return;