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/stm32mp157c-ev1-u-boot.dtsi b/arch/arm/dts/stm32mp157c-ev1-u-boot.dtsi
index 2f4de3a..30b1734 100644
--- a/arch/arm/dts/stm32mp157c-ev1-u-boot.dtsi
+++ b/arch/arm/dts/stm32mp157c-ev1-u-boot.dtsi
@@ -25,6 +25,10 @@
 	regulator-always-on;
 };
 
+&usbotg_hs {
+	g-tx-fifo-size = <576>;
+};
+
 /* SPL part **************************************/
 &qspi {
 	u-boot,dm-spl;
@@ -60,3 +64,4 @@
 &flash0 {
 	u-boot,dm-spl;
 };
+