[media] rc-core: Code cleanup after merging rc-sysfs and rc-map into rc-main

[mchehab@redhat.com: this patch were originally bundled with some renaming
stuff and with the file merges, as seen at:
https://patchwork.kernel.org/patch/291092/

.

Instead of using the original approach, I wrote the rename patches and the
code merge as separate changes, then applied the difference on this patch.
This way, it is easier to see the real changes at the code, and will be easier
to merge upstream, especially if some conflict rises on the renaming patches]

Signed-off-by: David Härdeman <david@hardeman.nu>
Acked-by: Jarod Wilson <jarod@redhat.com>
Tested-by: Jarod Wilson <jarod@redhat.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>