dm: pci: return the real controller in pci_bus_to_hose()

dm: pci: return the real controller in pci_bus_to_hose()

for the legacy PCI driver, the function pci_bus_to_hose() returns
the real PCIe controller. To keep consistency, this function is
changed to return the PCIe controller pointer of the root bus
instead of the current PCIe bus.

Signed-off-by: Minghuan Lian <[email protected]>
Signed-off-by: Hou Zhiqiang <[email protected]>
Reviewed-by: Simon Glass <[email protected]>
Reviewed-by: Bin Meng <[email protected]>
Reviewed-by: York Sun <[email protected]>