rcc: consistency fixes on f2

data/registers/rcc_f2.yaml

@@ -1147,14 +1147,16 @@ fieldset/PLLCFGR:
 fieldset/PLLI2SCFGR:
   description: PLLI2S configuration register
   fields:
-  - name: PLLI2SN
+  - name: PLLN
     description: PLLI2S multiplication factor for VCO
     bit_offset: 6
     bit_size: 9
-  - name: PLLI2SR
+    enum: PLLN
+  - name: PLLR
     description: PLLI2S division factor for I2S clocks
     bit_offset: 28
     bit_size: 3
+    enum: PLLR
 fieldset/SSCGR:
   description: spread spectrum clock generation register
   fields:
@@ -1920,6 +1922,21 @@ enum/PLLQ:
     value: 14
   - name: Div15
     value: 15
+enum/PLLR:
+  bit_size: 3
+  variants:
+  - name: Div2
+    value: 2
+  - name: Div3
+    value: 3
+  - name: Div4
+    value: 4
+  - name: Div5
+    value: 5
+  - name: Div6
+    value: 6
+  - name: Div7
+    value: 7
 enum/PLLSRC:
   bit_size: 1
   variants: