To be able to timely start the first CIS/CIG, if the requested instant
is the next connection event, call ull_peripheral_iso_start directly
from rp_cc_state_wait_rx_cis_ind instead of waiting for next time
through the state machine.
To enable ULL/LLL to prevent adding latency when LLCP is waiting for
instant, local- and remote procedures with instant now expose a function
for checking this state.
Fixed event_counter function to prevent one-off in RX path. Unified to
use single function ull_conn_event_counter.
Fixed LLCP unit tests and added new mock function.
Signed-off-by: Morten Priess <mtpr@oticon.com>