ARM: dts: stm32: enable USB HS on stm32f769-disco

This patch enables USB HS on stm32f749-disco in OTG (DRD) mode.
The USB connector used will determine the role of USB OTG controller.

Signed-off-by: Amelie Delaunay <amelie.delaunay@st.com>
Signed-off-by: Alexandre Torgue <alexandre.torgue@st.com>