V4L/DVB (12177): dm646x: Add an entry for dm646x EVM card at building system

Makefile and Kconfig changes for DM646x Video Display device, using
davinci/vpif, adv7343 and ths7303 drivers.

Signed-off-by: Manjunath Hadli <mrh@ti.com>
Signed-off-by: Brijesh Jadav <brijesh.j@ti.com>
Signed-off-by: Chaithrika U S <chaithrika@ti.com>
Signed-off-by: Hans Verkuil <hverkuil@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>