Several includes are not needed, so drop them.

of_platform.h is not needed, but it implicitly includes of.h which is
needed.
Signed-off-by: Rob Herring <robh@kernel.org>
Link: https://lore.kernel.org/r/20230717225704.3215469-1-robh@kernel.orgSigned-off-by: Florian Fainelli <florian.fainelli@broadcom.com>