Add new device as a child of the platform device, following the
following hierarchy:
platform_device
sdw_master_device
sdw_slave0
Why can't we just remove the platform device layer here and add
sdw_master_device directly?
What is it stopping doing that?
The guidance from Greg was "no platform devices, unless you really are
on a platform bus (i.e. Device tree.)". We never discussed changing the
way the Device Tree parts are handled.
The main idea was to leave the parent (be it platform-device or PCI
device) alone and not add new attributes or references to it.
The scheme here is similar to I2C/SPI, you have a platform device
handled by the Device Tree baseline, and a driver create an
i2c_adapter/spi_controller/sdw_master_device.
