mesh: Show peer connected time in the wpa_cli STA cmd output for Mesh mode

mesh: Show peer connected time in the wpa_cli STA cmd output for Mesh mode

When a Mesh interface is managed by wpa_supplicant, include the peer
link connected time (secs) in the output of "sta <addr>", "all_sta"
wpa_cli cmds for each peer. This will be helpful to find when the peer
link connection got established. The NL80211_STA_INFO_CONNECTED_TIME
netlink attribute data is used for this purpose if available.

$ wpa_cli -i mesh0 all_sta
02:00:00:00:02:00
flags=[ASSOC][WMM][HT]
aid=1
capability=0x0
listen_interval=0
supported_rates=82 84 8b 96 8c 12 98 24 b0 48 60 6c
timeout_next=NULLFUNC POLL
rx_packets=77
tx_packets=3
rx_bytes=8510
tx_bytes=284
inactive_msec=104
signal=-30
rx_rate_info=65 mcs 0
tx_rate_info=65 mcs 0
ht_mcs_bitmask=ffff0000000000000000
connected_time=24
ht_caps_info=0x103c

The connected_time field in the output of "hostapd_cli -i ap0 all_sta"
cmd is not affected and it will continue to show the connected time
maintained by hostapd for each STA.

Signed-off-by: Gokul Sivakumar <gokulkumar792@gmail.com>