Remove videobook.tmpl

This document describes the long-deprecated V4L1 interface.  In-tree, it
can only serve to encourage developers to write drivers to the wrong API.
Remove it in favor of the V4L2 documentation which must surely show up
someday.
Acked-by: Alan Cox <alan@redhat.com>
Acked-by: Mauro Carvalho Chehab <mchehab@infradead.org>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>

Documentation/DocBook/Makefile

@@ -6,7 +6,7 @@
 # To add a new book the only step required is to add the book to the
 # list of DOCBOOKS.
 
-DOCBOOKS := wanbook.xml z8530book.xml mcabook.xml videobook.xml \
+DOCBOOKS := wanbook.xml z8530book.xml mcabook.xml \
 	    kernel-hacking.xml kernel-locking.xml deviceiobook.xml \
 	    procfs-guide.xml writing_usb_driver.xml networking.xml \
 	    kernel-api.xml filesystems.xml lsm.xml usb.xml kgdb.xml \