PCI: ibmphp: stop managing hotplug_slot->name

We no longer need to manage our version of hotplug_slot->name
since the PCI and hotplug core manage it on our behalf.

Now, we simply advise the PCI core of the name that we would
like, and let the core take care of the rest.

Additionally, slightly rearrange the members of struct slot
so they are naturally aligned to eliminate holes.

Cc: jbarnes@virtuousgeek.org
Cc: kristen.c.accardi@intel.com
Acked-by: Kenji Kaneshige <kaneshige.kenji@jp.fujitsu.com>
Signed-off-by: Alex Chiang <achiang@hp.com>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>