ath9k: Fix regression on receiving PS poll frames

In the the patch:

ath9k: use new FIF_PSPOLL configure filter

I forgot to add the new FIF_PSPOLL to the supported mask.
Without this we mask out the FIF_PSPOLL flag therefore
we'd ignore it from mac80211.

Cc: Jouni Malinen <jouni.malinen@atheros.com>
Signed-off-by: NLuis R. Rodriguez <lrodriguez@atheros.com>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

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

@@ -2380,6 +2380,7 @@ static int ath9k_config(struct ieee80211_hw *hw, u32 changed)
 	(FIF_PROMISC_IN_BSS |			\
 	FIF_ALLMULTI |				\
 	FIF_CONTROL |				\
+	FIF_PSPOLL |				\
 	FIF_OTHER_BSS |				\
 	FIF_BCN_PRBRESP_PROMISC |		\
 	FIF_FCSFAIL)