Support STM32WLEx ADC peripheral

Use adc_g0 since very similar to the WLE one.

data/registers/rcc_wle.yaml

@@ -689,6 +689,7 @@ fieldset/CCIPR:
       description: ADC clock source selection
       bit_offset: 28
       bit_size: 2
+      enum: ADCSEL
     - name: RNGSEL
       description: RNG clock source selection
       bit_offset: 30
@@ -1044,3 +1045,15 @@ fieldset/PLLCFGR:
       description: Main PLL division factor for PLLRCLK
       bit_offset: 29
       bit_size: 3
+enum/ADCSEL:
+  bit_size: 2
+  variants:
+    - name: HSI16
+      description: HSI16 used as ADC clock source
+      value: 1
+    - name: PLLPCLK
+      description: PLLPCLK used as ADC clock source
+      value: 2
+    - name: SYSCLK
+      description: SYSCLK used as ADC clock source
+      value: 3