media: dt-bindings: ov5640: Add "rotation" property

Add the rotation property to the list of optional properties
for the OV5640 camera sensor.

Signed-off-by: Hugues Fruchet <hugues.fruchet@st.com>
Reviewed-by: Rob Herring <robh@kernel.org>
Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>