ath9k_hw: Fix system hang when resuming from S3/S4

The bit 6 & 7 of AR_WA (0x4004) should be enabled only
for the chips that are supporting L0s functionality
while resuming back from S3/S4.

Enabling these bits for AR9280 is causing system hang
within a few S3/S4-resume cycles.

Cc: stable@kernel.org
Cc: Jack Lee <jlee@atheros.com>
Signed-off-by: NRajkumar Manoharan <rmanoharan@atheros.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

drivers/net/wireless/ath/ath9k/ar9002_hw.c

@@ -426,9 +426,8 @@ static void ar9002_hw_configpcipowersave(struct ath_hw *ah,
 		}
 
 		/* WAR for ASPM system hang */
-		if (AR_SREV_9280(ah) || AR_SREV_9285(ah) || AR_SREV_9287(ah)) {
+		if (AR_SREV_9285(ah) || AR_SREV_9287(ah))
 			val |= (AR_WA_BIT6 | AR_WA_BIT7);
-		}
 
 		if (AR_SREV_9285E_20(ah))
 			val |= AR_WA_BIT23;