cfg80211: constify more pointers in the cfg80211 API

This also propagates through the drivers.

The orinoco driver uses the cfg80211 API structs for internal
bookkeeping, and so needs a (void *) cast that removes the
const - but that's OK because it allocates those pointers.

Signed-off-by: Johannes Berg <johannes.berg@intel.com>
diff --git a/net/wireless/sme.c b/net/wireless/sme.c
index 4bc21a2..ea701bb 100644
--- a/net/wireless/sme.c
+++ b/net/wireless/sme.c
@@ -879,7 +879,7 @@
 }
 
 void cfg80211_disconnected(struct net_device *dev, u16 reason,
-			   u8 *ie, size_t ie_len, gfp_t gfp)
+			   const u8 *ie, size_t ie_len, gfp_t gfp)
 {
 	struct wireless_dev *wdev = dev->ieee80211_ptr;
 	struct cfg80211_registered_device *rdev = wiphy_to_rdev(wdev->wiphy);