ath9k_hw: Fix power on reset

Commit "ath9k_hw: add an extra delay when reseting AR_RTC_RESET"
added an extra udelay to the reset routine. As the required
delay is already present, remove this.
Signed-off-by: NSujith Manoharan <Sujith.Manoharan@atheros.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

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

@@ -1100,7 +1100,6 @@ static bool ath9k_hw_set_reset_power_on(struct ath_hw *ah)
 		REG_WRITE(ah, AR_RC, AR_RC_AHB);
 
 	REG_WRITE(ah, AR_RTC_RESET, 0);
-	udelay(2);
 
 	REGWRITE_BUFFER_FLUSH(ah);