PCI: dwc: Drop support for config space in 'ranges'

Since commit a0fd361d ("PCI: dwc: Move "dbi", "dbi2", and
"addr_space" resource setup into common code"), the code
setting dbi_base when the config space is defined in 'ranges' property
instead of 'reg' is dead code as dbi_base is never NULL.

Rather than fix this, let's just drop the code. Using ranges has been
deprecated since 2014. The only platforms using this were exynos5440,
i.MX6 and Spear13xx. Exynos5440 is dead and has been removed. i.MX6 and
Spear13xx had PCIe support added just before this was deprecated and
were fixed within a kernel release or 2.

Link: https://lore.kernel.org/r/20201215194149.86831-1-robh@kernel.org


Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Rob Herring <robh@kernel.org>
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>