cfg80211: Specify the reason for connect timeout

This enhances the connect timeout API to also carry the reason for the
timeout. These reason codes for the connect time out are represented by
enum nl80211_timeout_reason and are passed to user space through a new
attribute NL80211_ATTR_TIMEOUT_REASON (u32).

Signed-off-by: Purushottam Kushwaha <pkushwah@qti.qualcomm.com>
Signed-off-by: Jouni Malinen <jouni@qca.qualcomm.com>
[keep gfp_t argument last]
Signed-off-by: Johannes Berg <johannes.berg@intel.com>