[media] dm644x: replace the obsolete preset API by the timings API

This patch replaces the preset API by the timings API, and
appropriate changes in board file.

Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Lad, Prabhakar <prabhakar.lad@ti.com>
Signed-off-by: Manjunath Hadli <manjunath.hadli@ti.com>
Acked-by: Sekhar Nori <nsekhar@ti.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>