ath9k: Fix rx filtering issue for older chips

We need to have the promiscuous mode enabled for older
chipsets so that the olderchips hardware does not
filters out some valid/necessary frames that need
to be sent to mac80211. Fix this by enabling promiscus
mode for all the chipsets whose macversion <= AR9160
chipsets. This should fix
https://bugzilla.kernel.org/show_bug.cgi?id=45591

shafi: made the fix generic by having the frame filtering
disabled for chipsets older than AR9280.

Cc: Javier Cardona <javier@cozybit.com>
Signed-off-by: Thomas Wagner <Thomas.Wagner@hs-rm.de>
Signed-off-by: Mohammed Shafi Shajakhan <mohammed@qca.qualcomm.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

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

@@ -424,8 +424,8 @@ u32 ath_calcrxfilter(struct ath_softc *sc)
 		rfilt |= ATH9K_RX_FILTER_COMP_BAR;
 
 	if (sc->nvifs > 1 || (sc->rx.rxfilter & FIF_OTHER_BSS)) {
-		/* The following may also be needed for other older chips */
-		if (sc->sc_ah->hw_version.macVersion == AR_SREV_VERSION_9160)
+		/* This is needed for older chips */
+		if (sc->sc_ah->hw_version.macVersion <= AR_SREV_VERSION_9160)
 			rfilt |= ATH9K_RX_FILTER_PROM;
 		rfilt |= ATH9K_RX_FILTER_MCAST_BCAST_ALL;
 	}