[media] nuvoton-cir: improve buffer parsing responsiveness

Rather than waiting for trigger bits, the formula for which was slightly
messy, and apparently, not actually 100% complete for some remotes, just
call ir_raw_event_handle whenever we finish parsing a chunk of data from
the rx fifo, similar to mceusb, as well as whenever we see an 'end of
signal data' 0x80 packet.

Signed-off-by: Jarod Wilson <jarod@redhat.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>