ARM: dts: stm32: Add USB FS support for STM32F746 MCU

This patch adds the USB pins and nodes for USB FS core on STM32F746 SoC.
Signed-off-by: Amelie Delaunay <amelie.delaunay@st.com>
Signed-off-by: Alexandre Torgue <alexandre.torgue@st.com>

arch/arm/boot/dts/stm32f746.dtsi

@@ -701,6 +701,17 @@ pins {
 					slew-rate = <2>;
 				};
 			};
+
+			usbotg_fs_pins_a: usbotg-fs@0 {
+				pins {
+					pinmux = <STM32_PINMUX('A', 10, AF10)>, /* OTG_FS_ID */
+						 <STM32_PINMUX('A', 11, AF10)>, /* OTG_FS_DM */
+						 <STM32_PINMUX('A', 12, AF10)>; /* OTG_FS_DP */
+					bias-disable;
+					drive-push-pull;
+					slew-rate = <2>;
+				};
+			};
 		};
 
 		crc: crc@40023000 {
@@ -762,6 +773,15 @@ usbotg_hs: usb@40040000 {
 			clock-names = "otg";
 			status = "disabled";
 		};
+
+		usbotg_fs: usb@50000000 {
+			compatible = "st,stm32f4x9-fsotg";
+			reg = <0x50000000 0x40000>;
+			interrupts = <67>;
+			clocks = <&rcc 0 STM32F7_AHB2_CLOCK(OTGFS)>;
+			clock-names = "otg";
+			status = "disabled";
+		};
 	};
 };