PCI: dwc: Reuse local pointer to the resource data

dw_pcie_host_init() has two instances of the resource structure pointers
used in unrelated places. It's pointless to have two different local
storages for them since the corresponding code is small and having
resource-specific names doesn't make it more readable.

Convert these parts of the function to use a common pointer to the
resource structure instance.

Link: https://lore.kernel.org/r/20220624143428.8334-13-Sergey.Semin@baikalelectronics.ru


Signed-off-by: Serge Semin <Sergey.Semin@baikalelectronics.ru>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Rob Herring <robh@kernel.org>
Reviewed-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>