board: gd32e103v_eval: add a prescaler for timer

add a prescaler for timer to have long time period

Signed-off-by: YuLong Yao <[email protected]>

Author: feilongfl

boards/arm/gd32e103v_eval/gd32e103v_eval.dts

@@ -102,6 +102,7 @@
 
 &timer0 {
 	status = "okay";
+	prescaler = <128>;
 
 	pwm0: pwm {
 		status = "okay";