of/platform: Add stubs for of_platform_device_create/destroy()

Code for platform_device_create() and of_platform_device_destroy() is
only generated if CONFIG_OF_ADDRESS=y. Add stubs to avoid unresolved
symbols when CONFIG_OF_ADDRESS is not set.

Acked-by: Rob Herring <robh@kernel.org>
Signed-off-by: Matthias Kaehlcke <mka@chromium.org>
Link: https://lore.kernel.org/r/20210609150159.v12.3.I08fd2e1c775af04f663730e9fb4d00e6bbb38541@changeid
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>