RC_DEVICES=y required post v3.4-rc7

[Russ Dill <russ.dill@gmail.com>]

A Kconfig re-org means that after v3.4-rc7, RC_DEVICES=y is required
for LIRC devices drivers to be compiled. A similar config option,
RC_DECODERS, was added around the same time, but was given a 'default
y'. This means that the linux-image-3.6-trunk images are compiled with
LIRC device drivers.