Revert "PCI: Assign PCI domain IDs by ida_alloc()"

This reverts commit f8b6bd6c which is
commit c14f7ccc upstream.

It breaks the Android kernel abi and can be brought back in the future
in an abi-safe way if it is really needed.

Bug: 161946584
Change-Id: Id289c8cc540a861c578a86ac2463e0f8f4cf1a1e
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>