PCI: acpiphp: Create companion ACPI devices before creating PCI devices

With commit 4f535093 "PCI: Put pci_dev in device tree as
early as possible", companion ACPI devices should be created before
creating corresponding PCI devices, otherwise it will break the ACPI
PCI binding logic.

Without this patch, the /sys/bus/pci/devices/.../firmware_node symlink
is missing after hot-removing and hot-adding a device with acpiphp.

Signed-off-by: Jiang Liu <jiang.liu@huawei.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>