dts/bindings/clocks: stm32l0-msi-clock: Use enum for allowed values

Use enum to describe the range of allowed MSI values.
This will help to detect configuration issues earlier.

Signed-off-by: Erwan Gouriou <[email protected]>

Author: erwango

dts/bindings/clock/st,stm32l0-msi-clock.yaml

@@ -17,10 +17,11 @@ properties:
       default: 5
       description: |
         MSI clock ranges
-        0: range 0 around 65.536 kHz
-        1: range 1 around 131.072 kHz
-        2: range 2 around 262.144 kHz
-        3: range 3 around 524.288 kHz
-        4: range 4 around 1.048 MHz
-        5: range 5 around 2.097 MHz (reset value)
-        6: range 6 around 4.194 MHz
+      enum:
+        - 0 # range 0, around 65.536 kHz
+        - 1 # range 1, around 131.072 kHz
+        - 2 # range 2, around 262.144 kHz
+        - 3 # range 3, around 524.288 kHz
+        - 4 # range 4, around 1.048 MHz
+        - 5 # range 5, around 2.097 MHz (reset value)
+        - 6 # range 6, around 4.194 MHz