ath9k: add noise floor parameter to ath9k_hw_getchan_noise

Add nf parameter to ath9k_hw_getchan_noise() in order to compute NF for EXT
chains with the same scale of noise floor calculated on CTL chains.
ath9k_hw_getchan_noise() will be used in ath_process_fft() for spectral scan on
HT40 channels

Signed-off-by: Lorenzo Bianconi <lorenzo.bianconi83@gmail.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
diff --git a/drivers/net/wireless/ath/ath9k/hw.c b/drivers/net/wireless/ath/ath9k/hw.c
index dcdbab4..54b0415 100644
--- a/drivers/net/wireless/ath/ath9k/hw.c
+++ b/drivers/net/wireless/ath/ath9k/hw.c
@@ -1885,7 +1885,7 @@
 	} else if (caldata) {
 		clear_bit(PAPRD_PACKET_SENT, &caldata->cal_flags);
 	}
-	ah->noise = ath9k_hw_getchan_noise(ah, chan);
+	ah->noise = ath9k_hw_getchan_noise(ah, chan, chan->noisefloor);
 
 	if (fastcc) {
 		r = ath9k_hw_do_fastcc(ah, chan);