dt-bindings: More use 'enum' instead of 'oneOf' plus 'const' entries

'enum' is equivalent to 'oneOf' with a list of 'const' entries, but 'enum'
is more concise and yields better error messages.

Fix a couple more cases which have appeared.

Cc: Rob Clark <robdclark@gmail.com>
Cc: Sean Paul <sean@poorly.run>
Cc: Mark Brown <broonie@kernel.org>
Cc: Wim Van Sebroeck <wim@linux-watchdog.org>
Cc: Guenter Roeck <linux@roeck-us.net>
Cc: Jonathan Marek <jonathan@marek.ca>
Cc: Aswath Govindraju <a-govindraju@ti.com>
Cc: Marc Zyngier <maz@kernel.org>
Cc: Linus Walleij <linus.walleij@linaro.org>
Cc: dri-devel@lists.freedesktop.org
Cc: freedreno@lists.freedesktop.org
Cc: linux-spi@vger.kernel.org
Cc: linux-watchdog@vger.kernel.org
Signed-off-by: Rob Herring <robh@kernel.org>
Acked-by: Guenter Roeck <linux@roeck-us.net>
Acked-by: Mark Brown <broonie@kernel.org>
Link: https://lore.kernel.org/r/20210910165153.2843871-1-robh@kernel.org

Documentation/devicetree/bindings/display/msm/dsi-phy-7nm.yaml

@@ -14,10 +14,10 @@ allOf:
 
 properties:
   compatible:
-    oneOf:
-      - const: qcom,dsi-phy-7nm
-      - const: qcom,dsi-phy-7nm-8150
-      - const: qcom,sc7280-dsi-phy-7nm
+    enum:
+      - qcom,dsi-phy-7nm
+      - qcom,dsi-phy-7nm-8150
+      - qcom,sc7280-dsi-phy-7nm
 
   reg:
     items:

Documentation/devicetree/bindings/spi/omap-spi.yaml

@@ -84,9 +84,9 @@ unevaluatedProperties: false
 if:
   properties:
     compatible:
-      oneOf:
-        - const: ti,omap2-mcspi
-        - const: ti,omap4-mcspi
+      enum:
+        - ti,omap2-mcspi
+        - ti,omap4-mcspi
 
 then:
   properties:

Documentation/devicetree/bindings/watchdog/maxim,max63xx.yaml

@@ -15,13 +15,13 @@ maintainers:
 
 properties:
   compatible:
-    oneOf:
-      - const: maxim,max6369
-      - const: maxim,max6370
-      - const: maxim,max6371
-      - const: maxim,max6372
-      - const: maxim,max6373
-      - const: maxim,max6374
+    enum:
+      - maxim,max6369
+      - maxim,max6370
+      - maxim,max6371
+      - maxim,max6372
+      - maxim,max6373
+      - maxim,max6374
 
   reg:
     description: This is a 1-byte memory-mapped address