ARM: dts: stm32: Fix HSE clock frequency for stm32h743i-disco board

The HSE oscillator frequency was wrongly set to 125MHz instead of 25MHz.
Signed-off-by: Patrice Chotard <patrice.chotard@st.com>
Signed-off-by: Alexandre Torgue <alexandre.torgue@st.com>

arch/arm/boot/dts/stm32h743i-disco.dts

@@ -63,7 +63,7 @@ aliases {
 };
 
 &clk_hse {
-	clock-frequency = <125000000>;
+	clock-frequency = <25000000>;
 };
 
 &usart2 {