V4L/DVB (5902): Add ivtv-fb framebuffer driver.

Add the ivtv-fb framebuffer driver for cx23415 devices (currently
only the Hauppauge PVR-350 cards). This makes it possible to use
the On-Screen Display functionality of these cards, either for menus
during MPEG playback, or as a console or X display.

Signed-off-by: Kevin Thayer <nufan_wfk@yahoo.com>
Signed-off-by: Chris Kennedy <c@groovy.org>
Signed-off-by: Hans Verkuil <hverkuil@xs4all.nl>
Signed-off-by: John P Harvey <john.p.harvey@btinternet.com>
Signed-off-by: Ian Armstrong <ian@iarmst.demon.co.uk>
Signed-off-by: Mauro Carvalho Chehab <mchehab@infradead.org>