ARM: dts: stm32mp1: Add usb gadget support for stm32mp157c-ev1 board

Add DT nodes to enable DWC2 gadget support

Signed-off-by: Patrice Chotard <patrice.chotard@st.com>
diff --git a/arch/arm/dts/stm32mp157-pinctrl.dtsi b/arch/arm/dts/stm32mp157-pinctrl.dtsi
index c69c397..85da592 100644
--- a/arch/arm/dts/stm32mp157-pinctrl.dtsi
+++ b/arch/arm/dts/stm32mp157-pinctrl.dtsi
@@ -321,6 +321,12 @@
 					bias-disable;
 				};
 			};
+
+			usbotg_hs_pins_a: usbotg_hs-0 {
+				pins {
+					pinmux = <STM32_PINMUX('A', 10, ANALOG)>; /* OTG_ID */
+				};
+			};
 		};
 
 		pinctrl_z: pin-controller-z@54004000 {