Update HALConfig.cpp

Added hal_enable_dual_mode() routine to access LL driver.

Author: jmdodd95682

src/HALConfig.cpp

@@ -166,6 +166,12 @@ static uint32_t ADC_RANK_LUT[] = {
     ADC_REGULAR_RANK_1, ADC_REGULAR_RANK_2, ADC_REGULAR_RANK_3, ADC_REGULAR_RANK_4, ADC_REGULAR_RANK_5
 };
 
+int hal_enable_dual_mode()
+{
+    LL_ADC_SetMultimode(__LL_ADC_COMMON_INSTANCE(ADC1), LL_ADC_MULTI_DUAL_REG_SIMULT);
+    return(1);
+}
+
 int hal_adc_config(ADC_HandleTypeDef *adc, uint32_t resolution, uint32_t trigger, PinName *adc_pins, uint32_t n_channels) {
     // Set ADC clock source.
     __HAL_RCC_ADC_CONFIG(RCC_ADCCLKSOURCE_CLKP);