pci: Use PCI PM capability initializer

pci: Use PCI PM capability initializer

Switch callers directly initializing the PCI PM capability with
pci_add_capability() to use pci_pm_init().

Cc: Dmitry Fleytman <dmitry.fleytman@gmail.com>
Cc: Akihiko Odaki <akihiko.odaki@daynix.com>
Cc: Jason Wang <jasowang@redhat.com>
Cc: Stefan Weil <sw@weilnetz.de>
Cc: Sriram Yagnaraman <sriram.yagnaraman@ericsson.com>
Cc: Keith Busch <kbusch@kernel.org>
Cc: Klaus Jensen <its@irrelevant.dk>
Cc: Jesper Devantier <foss@defmacro.it>
Cc: Michael S. Tsirkin <mst@redhat.com>
Cc: Marcel Apfelbaum <marcel.apfelbaum@gmail.com>
Cc: Cédric Le Goater <clg@redhat.com>
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
Reviewed-by: Eric Auger <eric.auger@redhat.com>
Reviewed-by: Akihiko Odaki <akihiko.odaki@daynix.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Link: https://lore.kernel.org/qemu-devel/20250225215237.3314011-3-alex.williamson@redhat.com
Signed-off-by: Cédric Le Goater <clg@redhat.com>