dt-bindings: use capital "OR" for multiple licenses in SPDX

Documentation/process/license-rules.rst and checkpatch expect the SPDX
identifier syntax for multiple licenses to use capital "OR".  Correct it
to keep consistent format and avoid copy-paste issues.

Correct also the format // -> .* in few Allwinner binding headers as
pointed out by checkpatch:

  WARNING: Improper SPDX comment style for 'include/dt-bindings/reset/sun50i-h6-ccu.h', please use '/*' instead

Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Acked-by: Guenter Roeck <linux@roeck-us.net>
Acked-by: Stephen Boyd <sboyd@kernel.org>
Link: https://lore.kernel.org/r/20230823084540.112602-1-krzysztof.kozlowski@linaro.org
Signed-off-by: Rob Herring <robh@kernel.org>