staging: vchiq_shim: delete vchi_service_create

No one is using the API neither in the actual staging tree nor in the
downstream tree (https://github.com/raspberrypi/linux

).

Signed-off-by: Nicolas Saenz Julienne <nsaenzjulienne@suse.de>
Acked-by: Stefan Wahren <stefan.wahren@i2se.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>