PCI: pciehp: remove number field

Since slot_cap field in struct controller contains physical slot
number informationq, we don't need number field in struct slot.

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