drm/nouveau: deprecate pci_get_bus_and_slot()

pci_get_bus_and_slot() is restrictive such that it assumes domain=0 as
where a PCI device is present. This restricts the device drivers to be
reused for other domain numbers.

Getting ready to remove pci_get_bus_and_slot() function in favor of
pci_get_domain_bus_and_slot().

Replace pci_get_bus_and_slot() with pci_get_domain_bus_and_slot()
and extract the domain number from
1. struct pci_dev
2. struct pci_dev through drm_device->pdev
3. struct pci_dev through fb->subdev->drm_device->pdev

Signed-off-by: Sinan Kaya <okaya@codeaurora.org>
Signed-off-by: Bjorn Helgaas <helgaas@kernel.org>