of/platform: Use platform_device interface

of_platform_device_create_pdata() was using of_device_add() to create
the devices, but of_platform_device_destroy was using
platform_device_unregister() to free them.

of_device_add(), do not call insert_resource(), which initializes the
parent field of the resource structure, needed by release_resource(),
called by of_platform_device_destroy(). This leads to a NULL pointer
deference.

Instead of fixing the NULL pointer deference, what could hide other bugs,
this patch, replaces of_device_add() with platform_device_data().

Signed-off-by: Ricardo Ribalda Delgado <ricardo.ribalda@gmail.com>
Acked-by: Rob Herring <robh@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>