p54: Add quality output to iwlist and iwconfig

The p54 driver family reports a quality of 0 in iwconfig and iwlist
output. This patch calculates a quality number as a percentage of the
rssi to the maximum signal of 127 reported as the maximum signal.
Signed-off-by: NLarry Finger <Larry.Finger@lwfinger.net>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

drivers/net/wireless/p54/p54common.c

@@ -357,6 +357,7 @@ static void p54_rx_data(struct ieee80211_hw *dev, struct sk_buff *skb)
 
 	rx_status.signal = hdr->rssi;
 	/* XX correct? */
+	rx_status.qual = (100 * hdr->rssi) / 127;
 	rx_status.rate_idx = hdr->rate & 0xf;
 	rx_status.freq = freq;
 	rx_status.band = IEEE80211_BAND_2GHZ;