PCI: dwc: Check iATU in/outbound range setup status

Make the DWC PCIe RC/EP safer and more verbose for invalid or failed
inbound and outbound iATU window setups.  Silently ignoring iATU regions
setup errors may cause unpredictable errors. For instance if a cfg or IO
window fails to be activated, then any CFG/IO requested won't reach target
PCIe devices and the corresponding accessors will return platform-specific
random values.

[bhelgaas: trim commit log]
Link: https://lore.kernel.org/r/20220624143947.8991-15-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>