ARM: dts: stm32: Sync DT with v4.20 kernel for stm32h7

Synchronize stm32h7 device tree with kernel v4.20.
U-boot DT files and pinctrl bindings are updated,
useless nodes are removed and gpio compatible added.

Signed-off-by: Patrice Chotard <patrice.chotard@st.com>
diff --git a/arch/arm/dts/stm32h743i-disco.dts b/arch/arm/dts/stm32h743i-disco.dts
index 1237a81..45e088c 100644
--- a/arch/arm/dts/stm32h743i-disco.dts
+++ b/arch/arm/dts/stm32h743i-disco.dts
@@ -62,9 +62,12 @@
 	};
 };
 
+&clk_hse {
+	clock-frequency = <25000000>;
+};
+
 &usart2 {
 	pinctrl-0 = <&usart2_pins>;
 	pinctrl-names = "default";
 	status = "okay";
 };
-