Bridge primary, secondary, and subordinate bus numbers power up as zero,
and Tegra firmware doesn't program them.

pci_scan_bridge_extend() automatically programs these bus numbers if they
are zero, so we don't need to set the PCI_REASSIGN_ALL_BUS flag for Tegra.
Signed-off-by: NManikanta Maddireddy <mmaddireddy@nvidia.com>
[bhelgaas: changelog]
Signed-off-by: NBjorn Helgaas <helgaas@kernel.org>
Acked-by: NThierry Reding <treding@nvidia.com>