[media] Add the via framebuffer camera controller driver

Add a driver for the video capture port on VIA integrated chipsets.  This
version has a remaining OLPCism or two and expects to be talking to an
ov7670; those can be improved as the need arises.

This work was supported by the One Laptop Per Child project.
Thanks to Laurent Pinchart for a number of useful comments.

Cc: Florian Tobias Schandinat <FlorianSchandinat@gmx.de>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>

include/media/v4l2-chip-ident.h

@@ -115,6 +115,10 @@ enum {
 	V4L2_IDENT_VPX3216B = 3216,
 	V4L2_IDENT_VPX3220A = 3220,
 
+	/* VX855 just ident 3409 */
+	/* Other via devs could use 3314, 3324, 3327, 3336, 3364, 3353 */
+	V4L2_IDENT_VIA_VX855 = 3409,
+
 	/* module tvp5150 */
 	V4L2_IDENT_TVP5150 = 5150,