Bluetooth: L2CAP: Handle LE connection response security errors

If there are security errors bump the security of the connection and
retry:

7C:7A:91:18:82:5F (public)> l2cap-connect 0x0080
[bt] [DBG] bt_l2cap_chan_connect: (0x0011ae8c) conn 0x0011b940 chan 0x00119700 psm 0x0080
[bt] [DBG] l2cap_chan_tx_init: (0x0011ae8c) chan 0x00119700
[bt] [DBG] l2cap_chan_rx_init: (0x0011ae8c) chan 0x00119700
[bt] [DBG] bt_l2cap_chan_add: (0x0011ae8c) conn 0x0011b940 chan 0x00119700
L2CAP connection pending
7C:7A:91:18:82:5F (public)> [bt] [DBG] bt_l2cap_recv: (0x0011ced8) Packet for CID 5 len 14
[bt] [DBG] l2cap_chan_recv: (0x0011ced8) chan 0x0011bd00 len 14
[bt] [DBG] l2cap_recv: (0x0011ced8) Signaling code 0x15 ident 2 len 10
[bt] [DBG] le_conn_rsp: (0x0011ced8) dcid 0x0000 mtu 0 mps 0 credits 0 result 0x0005
[bt] [DBG] bt_l2cap_recv: (0x0011ced8) Packet for CID 6 len 7
[bt] [DBG] l2cap_chan_recv: (0x0011ced8) chan 0x0011bf00 len 7
[bt] [DBG] bt_l2cap_recv: (0x0011ced8) Packet for CID 6 len 65
[bt] [DBG] l2cap_chan_recv: (0x0011ced8) chan 0x0011bf00 len 65
[bt] [DBG] bt_l2cap_recv: (0x0011ced8) Packet for CID 6 len 17
[bt] [DBG] l2cap_chan_recv: (0x0011ced8) chan 0x0011bf00 len 17
[bt] [DBG] bt_l2cap_recv: (0x0011ced8) Packet for CID 6 len 17
[bt] [DBG] l2cap_chan_recv: (0x0011ced8) chan 0x0011bf00 len 17
Security changed: 7C:7A:91:18:82:5F (public) level 2
[bt] [DBG] bt_l2cap_recv: (0x0011ced8) Packet for CID 5 len 14
[bt] [DBG] l2cap_chan_recv: (0x0011ced8) chan 0x0011bd00 len 14
[bt] [DBG] l2cap_recv: (0x0011ced8) Signaling code 0x15 ident 3 len 10
[bt] [DBG] le_conn_rsp: (0x0011ced8) dcid 0x0040 mtu 672 mps 230 credits 10 result 0x0000
Channel 0x00119700 connected

Change-Id: I2402fd86cc6bdf41a537053325e0a1973c23377a
Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>