The existing queue initialization function would always sets it's
maximum queue size to ctx->queue_size.  But because we are introducing
more queues we may want the sizes to differ between them.

Move the specification of the queue size into an argument, which can
be passed from the caller.

This patch makes no functional change to the behavior.  It is being
made to accommodate Marton Balin's request to split out the queue
size for the new VANC queue being introduced in a later patch.
Signed-off-by: Devin Heitmueller <dheitmueller@ltnglobal.com>
Signed-off-by: Marton Balint <cus@passwd.hu>