of: Constify of_changeset_entry function arguments

__of_changeset_entry_invert() and __of_changeset_entry_revert() don't
modify struct of_changeset_entry arguments, so they can be const.

Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Link: https://lore.kernel.org/r/20241010-dt-const-v1-5-87a51f558425@kernel.org


Signed-off-by: Rob Herring (Arm) <robh@kernel.org>