dt-bindings: opp: Allow multi-worded OPP entry name

Not all OPP entries fit into a single word. In particular NVIDIA Tegra OPP
tables use multi-word names. Allow OPP entry to have multi-worded name
separated by hyphen. This silences DT checker warnings about wrong naming
scheme.
Reviewed-by: David Heidelberg <david@ixit.cz>
Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>

Documentation/devicetree/bindings/opp/opp-v2-base.yaml

@@ -33,7 +33,7 @@ properties:
     type: boolean
 
 patternProperties:
-  '^opp-?[0-9]+$':
+  '^opp(-?[0-9]+)*$':
     type: object
     description:
       One or more OPP nodes describing voltage-current-frequency combinations.