staging: vchiq: Export vchiq_msg_queue_push

vchiq consumer drivers may need to use this function in order to get the
benefits of vchiq's per service message queueing mechanism.
Signed-off-by: Nicolas Saenz Julienne <nsaenzjulienne@suse.de>
Link: https://lore.kernel.org/r/20200629150945.10720-28-nsaenzjulienne@suse.deSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/staging/vc04_services/interface/vchiq_arm/vchiq_if.h

@@ -107,6 +107,7 @@ extern enum vchiq_status vchiq_use_service(unsigned int service);
 extern enum vchiq_status vchiq_release_service(unsigned int service);
 extern enum vchiq_status vchiq_queue_kernel_message(unsigned int handle,
 						    void *context, size_t size);
+extern void vchiq_msg_queue_push(unsigned handle, struct vchiq_header *header);
 extern void           vchiq_release_message(unsigned int service,
 	struct vchiq_header *header);
 extern enum vchiq_status vchiq_bulk_transmit(unsigned int service,