tests: drivers: adc: Correct the reference-mv in Kconfig

Correct reference-mv in Kconfig of adc_accuracy_test

Signed-off-by: Khoa Nguyen <[email protected]>

Author: khoa-nguyen-18

tests/drivers/adc/adc_accuracy_test/Kconfig

@@ -15,7 +15,7 @@ config DAC_SOURCE_TEST
 
 config REFERENCE_VOLTAGE_TEST
 	bool
-	default y if $(dt_node_has_prop,/$(ZEPHYR_USER),reference_mv)
+	default y if $(dt_node_has_prop,/$(ZEPHYR_USER),reference-mv)
 
 config NUMBER_OF_PASSES
 	int "Number of passes"