PCI: cadence: Remove private bus number and range storage

There's no need to store the bus number or range resource as the driver
only needs the bus number which is already in the pci_host_bridge.

For endpoint mode, the bus number is always 0.

Link: https://lore.kernel.org/r/20200722022514.1283916-14-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>