PCI: imx6: Identify controller via 'linux,pci-domain', not address

PCI: imx6: Identify controller via 'linux,pci-domain', not address

Instead of testing the controller register address to distinguish
controller 1 from controller 0 on i.MX8MQ platforms, use the PCI domain
number, which comes from the devicetree 'linux,pci-domain' property.

All relevant devicetrees should already supply 'linux,pci-domain', which
was added by c0b70f05c87f ("arm64: dts: imx8mq: use_dt_domains for pci
node").

Instead of being set directly in imx_pcie_probe(), pci->dbi_base will be
set by the DWC core in dw_pcie_get_resources().

No functional changes intended.

Signed-off-by: Richard Zhu <hongxing.zhu@nxp.com>
Signed-off-by: Krzysztof Wilczyński <kwilczynski@kernel.org>
[bhelgaas: commit log]
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Frank Li <Frank.Li@nxp.com>
Link: https://lore.kernel.org/r/20250226024256.1678103-3-hongxing.zhu@nxp.com