PCI: tegra: Update PCI config space remap function

PCI configuration space should be mapped with a memory region type that
generates on the CPU host bus non-posted write transations. Update the
driver to use correct memory mapping attributes to map config space
regions to enforce configuration space non-posted writes behaviour.

Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Cc: Thierry Reding <thierry.reding@gmail.com>