PCI: host: Add of_pci_get_host_bridge_resources() stub

The pcie-rcar driver can be built for any ARM platform (for COMPILE_TEST)
including those without CONFIG_OF enabled, and that results in a
compile-time error:

  drivers/pci/host/pcie-rcar.c: In function 'rcar_pcie_parse_request_of_pci_ranges':
  drivers/pci/host/pcie-rcar.c:939:8: error: implicit declaration of function 'of_pci_get_host_bridge_resources' [-Werror=implicit-function-declaration]
    err = of_pci_get_host_bridge_resources(np, 0, 0xff, &pci->resources, &iobase);

Add a of_pci_get_host_bridge_resources() stub function defined when
CONFIG_OF_ADDRESS is disabled to allow compile-testing on all platforms.
This mirrors what we do for other OF-specific functions.

Fixes: 5d2917d4

 ("PCI: rcar: Convert to DT resource parsing API")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Acked-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Acked-by: Simon Horman <horms+renesas@verge.net.au>