pci: apple: Initialize only enabled ports

The Linux devicetrees for Apple silicon devices are after review
feedback switching from deleting unused PCIe ports to disabling them.

Link: https://lore.kernel.org/asahi/1ea2107a-bb86-8c22-0bbc-82c453ab08ce@linaro.org/


Signed-off-by: Janne Grunau <j@jannau.net>
Reviewed-by: Mark Kettenis <kettenis@openbsd.org>