[media] rc-core: fix various sparse warnings

Fix various sparse warnings under drivers/media/rc/*.c, mostly
by making functions static.

Signed-off-by: David Härdeman <david@hardeman.nu>
Signed-off-by: Mauro Carvalho Chehab <m.chehab@samsung.com>

diff --cc drivers/media/rc/fintek-cir.c
Simple merge

diff --cc drivers/media/rc/imon.c
Simple merge

diff --cc drivers/media/rc/ite-cir.c
Simple merge

diff --cc drivers/media/rc/nuvoton-cir.c
Simple merge