l2cap: validate LE signaling command length

l2cap: check SDU len against provided buffer, prevent buffer overrun during reassembly

l2cap: verify signaling len for CONNECTION_RESPONSE, CONFIGURE_REQUEST, CONFIGURE_RESPONSE

l2cap: verify signaling command len for CONNECTION_REQUEST, INFORMATION_REQUEST, and INFORMATION_RESPONSE

l2cap: assert classic signaling command has valid data len

l2cap: split l2cap_acl_handler into seperate LE and Classic handlers. Classic: Signaling, Connection-less, Classic channels. LE: LE Signaling, ATT, SM, LE Data Channels

l2cap: abort outgoing connection if SSP supported, LEVEL0 is not enough and security update fails

l2cap: fix compile

l2cap: fix compile

l2cap: emit L2CAP_EVENT_CHANNEL_OPENED with status L2CAP_CONNECTION_BASEBAND_DISCONNECT on HCI Disconnect Event before channel was opened

l2cap: fix regression sending config options - introduced in ERTM feature merge

l2cap: avoid unused parameter warning

l2cap: introduce parameter object l2cap_ertm_config_t for l2cap_create_ertm_channel and l2cap_accept_ertm_connection

l2cap: introduce l2cap_config_option_type_t

l2cap: introduce l2cap_info_type_t

l2cap-ertm: keep track of unacknowledged i-frames in unacked_frames field

l2cap-ertm: fix l2cap data dispatch for ertm

l2cap-ertm: stop monitor timer on RR/F=1

l2cap-ertm: review use of retransmission timer

l2cap-ertm: collect all ERTM-only function at the beginning

l2cap-ertm: extract l2cap_ertm_stop_retransmission_timer

l2cap-ertm: move retransmission and monitor timers into l2cap_channel, extract l2cap_ertm_start_retransmission_timer and l2cap_ertm_start_monitor_timer

l2cap-ertm: extract l2cap_ertm_can_store_packet_now, implement l2cap_ertm_notify_channel_can_send, support l2cap_request_can_send_now_event for ERTM connections

l2cap-ertm: implement l2cap_can_send_packet_now for ERTM

l2cap-ertm: set final bit for RR with p=1 in S-REJ, process stored frames and send updated S-RR