fiq_fsm: enable by default
fiq_fsm: clear hcintmsk for aborted transactions

Prevents the FIQ from erroneously handling interrupts
on a timed out channel.
fiq_fsm: save PID on completion of interrupt OUT transfers

Also add edge case handling for interrupt transports.

Note that for periodic split IN, data toggles are unimplemented in the
OTG host hardware - it unconditionally accepts any PID.
fiq_fsm: add missing case for fiq_fsm_tt_in_use()

Certain combinations of bitrate and endpoint activity could
result in a periodic transaction erroneously getting started
while the previous Isochronous OUT was still active.
fiq_fsm: fix bounce buffer utilisation for Isochronous OUT

Multi-packet isochronous OUT transactions were subject to a few bounday
bugs. Fix them.

Audio playback is now much more robust: however, an issue stands with
devices that have adaptive sinks - ALSA plays samples too fast.

fiq_fsm: fix dequeueing on non-periodic endpoints

If a dequeue was issued during the delay time between a SSPLIT and a CSPLIT,
the HCD did not get an interrupt passed through. Make SOF respond on dequeues.