alpha/PCI: Use PCI resource accessor macros

alpha/PCI: Use PCI resource accessor macros

Replace direct pdev->resource[] accesses with pci_resource_n(), and
open-coded res->flags type checks with pci_resource_is_mem() and
pci_resource_start() helpers.

While at it, move the pci_resource_n() call directly into
pcibios_resource_to_bus() and drop the local struct resource pointer.

No functional changes intended.

Signed-off-by: Krzysztof Wilczyński <kwilczynski@kernel.org>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Tested-by: Magnus Lindholm <linmag7@gmail.com>
Tested-by: Shivaprasad G Bhat <sbhat@linux.ibm.com>
Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Acked-by: Magnus Lindholm <linmag7@gmail.com>
Link: https://patch.msgid.link/20260508043543.217179-14-kwilczynski@kernel.org