[media] mceusb: fix up reporting of trailing space

We were storing a bunch of spaces at the end of each signal, rather than
a single long space. The in-kernel decoders were actually okay with
this, but lirc isn't. As suggested by David Härdeman, switch to storing
samples using ir_raw_event_store_with_filter, which auto-merges the
consecutive space samples for us. This also allows us to bypass having
to store rawir samples in our device struct, further simplifying the
buffer parsing state machine. Both in-kernel decoders and lirc are happy
again with this change.

Also included in this patch is proper parsing of 0x9f 0x01 commands, the
removal of some magic number usage and some printk spew fixups.

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