PCI: tegra: Remove unnecessary tegra_pcie_fixup_bridge()

The bridge setup is already done by generic code while scanning the buses.
Do not duplicate (or potentially alter) this setup as a fixup.

Tested-by: Alexandre Courbot <acourbot@nvidia.com>
Tested-by: Thierry Reding <treding@nvidia.com>
Signed-off-by: Lucas Stach <l.stach@pengutronix.de>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Thierry Reding <treding@nvidia.com>
Acked-by: Thierry Reding <treding@nvidia.com>