V4L/DVB: rename sysfs remote controller devices from rcrcv to rc

When the remote controller class is anyway being renamed from ir to rc
this would be a good time to also rename the devices from rcrcvX to rcX.

I know we haven't reached any agreement on whether transmission will
eventually be handled by the same device, but this change will at
least make the device name non-receive-specific which will make it
possible in the future (and if a different approach is finally
agreed upon, the device name still works).

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