staging: vc04_services: remove unused function

vchiq_get_service_fourcc() doesn't seem to be used anywhere

Signed-off-by: Marcelo Diop-Gonzalez <marcgonzalez@google.com>
Link: https://lore.kernel.org/r/ed8b0034e316b2a81b621e9fca43f8368334b191.1581532523.git.marcgonzalez@google.com


Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>