[PATCH v3] create modalias file in sysfs for bus of_platform

[Paul Mackerras]

Olaf Hering writes:

> Create /sys/bus/of_platform/devices/*/modalias file to allow autoloading
> of modules. modalias files are already present for many other bus types.

This one causes various oopses on boot for me, both on a dual G5 and
on a tibook.

Paul.