ARM: dts: stm32: Add USB OTG ID pin on DH AV96

Add USB OTG ID pin mux and switch the USB OTG port
from peripheral to OTG mode.

Signed-off-by: Marek Vasut <marex@denx.de>
Cc: Patrice Chotard <patrice.chotard@st.com>
Cc: Patrick Delaunay <patrick.delaunay@st.com>
Reviewed-by: Patrick Delaunay <patrick.delaunay@foss.st.com>