media: ov5640: add support of DVP parallel interface

Add support of DVP parallel mode in addition of
existing MIPI CSI mode. The choice between two modes
and configuration is made through device tree.

Signed-off-by: Hugues Fruchet <hugues.fruchet@st.com>
Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>