cfg80211: make connect ie param const

This required liberally sprinkling 'const' over brcmfmac
and mwifiex but seems like a useful thing to do since the
pointer can't really be written.

Signed-off-by: Johannes Berg <johannes.berg@intel.com>
diff --git a/include/net/cfg80211.h b/include/net/cfg80211.h
index 9237b26..d10ba3a 100644
--- a/include/net/cfg80211.h
+++ b/include/net/cfg80211.h
@@ -1737,7 +1737,7 @@
 	const u8 *ssid;
 	size_t ssid_len;
 	enum nl80211_auth_type auth_type;
-	u8 *ie;
+	const u8 *ie;
 	size_t ie_len;
 	bool privacy;
 	enum nl80211_mfp mfp;