p54: Support boottime in scan results

This patch fixes an issue with wpa_supplicant dropping all scan
results because their where considered to be "too old" (e.g.:
"skip - scan result not recent enough (121056.086325 seconds too old)")
which is very weird because this looks like that the scan results have
been received before a scan started. This is due to the inaccuracy of
the default timing mechanism for calculating the BSS entry age.
Signed-off-by: Christian Lamparter <chunkeey@gmail.com>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>

drivers/net/wireless/intersil/p54/txrx.c

@@ -334,6 +334,7 @@ static int p54_rx_data(struct p54_common *priv, struct sk_buff *skb)
 	u16 freq = le16_to_cpu(hdr->freq);
 	size_t header_len = sizeof(*hdr);
 	u32 tsf32;
+	__le16 fc;
 	u8 rate = hdr->rate & 0xf;
 
 	/*
@@ -382,6 +383,11 @@ static int p54_rx_data(struct p54_common *priv, struct sk_buff *skb)
 
 	skb_pull(skb, header_len);
 	skb_trim(skb, le16_to_cpu(hdr->len));
+
+	fc = ((struct ieee80211_hdr *)skb->data)->frame_control;
+	if (ieee80211_is_probe_resp(fc) || ieee80211_is_beacon(fc))
+		rx_status->boottime_ns = ktime_get_boot_ns();
+
 	if (unlikely(priv->hw->conf.flags & IEEE80211_CONF_PS))
 		p54_pspoll_workaround(priv, skb);