[media] rc: New rc-based ite-cir driver for several ITE CIRs

This is a second version of an rc-core based driver for the ITE Tech IT8712F
CIR and now for a pair of other variants of the IT8512 CIR too.

This driver should replace the lirc_it87 and lirc_ite8709 currently living in
the LIRC staging directory.

The driver should support the ITE8704, ITE8713, ITE8708 and ITE8709 (this last
one yet untested) PNP ID's.

The code doesn'te reuse code from the pre-existing LIRC drivers, but has been
written from scratch using the nuvoton.cir driver as a skeleton.

This new driver shouldn't exhibit timing problems when running under load (or
with interrupts disabled for relatively long times). It works OOTB with the
RC6 MCE remote bundled with the ASUS EEEBox. TX support is implemented, but
I'm unable to test it since my hardware lacks TX capability.

Signed-off-by: Juan J. Garcia de Soria <skandalfo@gmail.com>
Tested-by: Stephan Raue <stephan@openelec.tv>
Signed-off-by: Jarod Wilson <jarod@redhat.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>