of: address: Reshuffle to remove forward declarations

Reshuffle the code to get rid of the forward declarations, which
improves readability.

Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Link: https://lore.kernel.org/r/b8701c04d27e51618444a747c4f4be5cc889ce28.1680248888.git.geert+renesas@glider.be


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