doc: stm32f3: adc: add missing parameters

Minor, link the adc peripheral parameter in a couple of places

lib/stm32/f3/adc.c

@@ -587,10 +587,10 @@ void adc_set_injected_offset(uint32_t adc, uint8_t reg, uint32_t offset)
  *
  * The ADC clock taken from the APB2 clock can be scaled down by 2, 4, 6 or 8.
  *
+ * @param adc peripheral of choice @ref adc_reg_base
  * @param[in] prescale Unsigned int32. Prescale value for ADC Clock @ref
  * adc_ccr_adcpre
-*/
-
+ */
 void adc_set_clk_prescale(uint32_t adc, uint32_t prescale)
 {
 	uint32_t reg32 = ((ADC_CCR(adc) & ~ADC_CCR_CKMODE_MASK) | prescale);
@@ -605,10 +605,10 @@ void adc_set_clk_prescale(uint32_t adc, uint32_t prescale)
  *
  * The various modes possible are described in the reference manual.
  *
+ * @param adc peripheral of choice @ref adc_reg_base
  * @param[in] mode Unsigned int32. Multiple mode selection from @ref
  * adc_multi_mode
-*/
-
+ */
 void adc_set_multi_mode(uint32_t adc, uint32_t mode)
 {
 	ADC_CCR(adc) |= mode;