[media] davinci vpbe: add dm365 VPBE display driver changes

This patch implements the core additions to the display driver,
mainly controlling the VENC and other encoders for dm365.
This patch also includes addition of amplifier subdevice to the
vpbe driver and interfacing with venc subdevice.

Signed-off-by: Manjunath Hadli <manjunath.hadli@ti.com>
Acked-by: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>