dts: arm: stm32f303 vref characteristics is 3V

The vref has to be set to 3000mV.
It is the voltage to find on the stm32F3.
is fixed by the platform to be lower or equal to VDDA.

Signed-off-by: Francois Ramu <[email protected]>

Author: FRASTM

dts/arm/st/f3/stm32f303.dtsi

@@ -134,7 +134,7 @@
 			clocks = <&rcc STM32_CLOCK_BUS_AHB1 0x10000000>;
 			interrupts = <18 0>;
 			status = "disabled";
-			vref-mv = <3300>;
+			vref-mv = <3000>;
 			#io-channel-cells = <1>;
 			has-temp-channel;
 			has-vref-channel;