[media] ARM: dts: STiH407-family: add DELTA dt node

This patch adds DT node for STMicroelectronics
DELTA V4L2 video decoder

Signed-off-by: Hugues Fruchet <hugues.fruchet@st.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>