ARM: dts: stm32: enable USB OTG Dual Role on stm32mp157c-ev1

Now that st,stm32mp15-hsotg is used, dual role is supported. ID pin is
managed to detect the current role.
On stm32mp157c-ev1, Host mode requires a vbus-supply property. Charge pump
for vbus is provided by PMIC VBUS_OTG.

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