media: lirc: lirc interface should not be a raw decoder

The lirc user interface exists as a raw decoder, which does not make
much sense for transmit-only devices.

In addition, we want to have lirc char devices for devices which do not
use raw IR, i.e. scancode only devices.

Note that rc-code, lirc_dev, ir-lirc-codec are now calling functions of
each other, so they've been merged into one module rc-core to avoid
circular dependencies.

Since ir-lirc-codec no longer exists as separate codec module, there is no
need for RC_DRIVER_IR_RAW_TX type drivers to call ir_raw_event_register().

Signed-off-by: Sean Young <sean@mess.org>
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>