Documentation/kernel-docs.txt: add two published books

Add two books from my own bookshelf. I found them useful by
the time I bought; so it could be useful to others ;)

Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
1 file changed