PCI: Remove struct pci_devres.enabled status bit

PCI: Remove struct pci_devres.enabled status bit

The struct pci_devres has a separate boolean to track whether a device is
enabled. That, however, can easily be tracked in an agnostic manner through
the function pci_is_enabled().

Using it allows for simplifying the PCI devres implementation.

Replace the separate 'enabled' status bit from struct pci_devres with
calls to pci_is_enabled() at the appropriate places.

Link: https://lore.kernel.org/r/20240613115032.29098-8-pstanner@redhat.com
Signed-off-by: Philipp Stanner <pstanner@redhat.com>
Signed-off-by: Krzysztof Wilczyński <kwilczynski@kernel.org>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>