PCI: cadence: Use bridge resources for outbound window setup

Instead of parsing 'ranges' from DT again, use the bridge window
resources.

Link: https://lore.kernel.org/r/20200722022514.1283916-13-robh@kernel.org


Signed-off-by: Rob Herring <robh@kernel.org>
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Acked-by: Bjorn Helgaas <bhelgaas@google.com>
Cc: Tom Joseph <tjoseph@cadence.com>
Cc: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Cc: Bjorn Helgaas <bhelgaas@google.com>