PCI: rockchip: Drop storing driver private outbound resource data

The Rockchip host bridge driver doesn't need to store outboard resources
in its private struct as they are already stored in struct
pci_host_bridge.

Signed-off-by: Rob Herring <robh@kernel.org>
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Cc: Shawn Lin <shawn.lin@rock-chips.com>
Cc: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Cc: Andrew Murray <andrew.murray@arm.com>
Cc: Bjorn Helgaas <bhelgaas@google.com>
Cc: Heiko Stuebner <heiko@sntech.de>
Cc: linux-rockchip@lists.infradead.org