[Resend] pcibios_add_platform_entries usage

[Sebastian Ott <sebott@linux.vnet.ibm.com>]

Hello Bjorn,

for pci on s390 we currently use pcibios_add_platform_entries to add
some arch specific attributes to pdevs. This has 2 downsides - it will
race with userspace which is triggered by udev events and expecting
these attributes (but that's a theoretical issue). More important to
me is that one cannot use attribute_groups with this. Both issues could
be addressed by using pdev->dev.groups and let the driver core handle
attribute creation.

So would it be ok if we set pdev->dev.groups in pcibios_add_device?
(It should be since it's not used by pci common code which uses bus_type,
dev_type, and class groups).

Regards,
Sebastian