staging: vchi: Move vchi_queue_kernel_message() into vchiq

We can't really merge it with vchiq_queue_message() as it has internal
users that will not benefit from the retry mechanism
vchiq_queue_kernel_message() uses. So, for the sake of getting rid of
vchi, move it into vchiq.

Signed-off-by: Nicolas Saenz Julienne <nsaenzjulienne@suse.de>
Link: https://lore.kernel.org/r/20200629150945.10720-43-nsaenzjulienne@suse.de


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