PCI: imx6: Drop unnecessary root_bus_nr setting

Function dw_pcie_host_init() already initializes the root_bus_nr field
of 'struct pcie_port', so the -1 assignment prior to calling
dw_pcie_host_init() in platform specific driver is not really needed.
Drop it.

Signed-off-by: Shawn Guo <[email protected]>
Signed-off-by: Lorenzo Pieralisi <[email protected]>
Reviewed-by: Lucas Stach <[email protected]>
Cc: Richard Zhu <[email protected]>
Cc: Lucas Stach <[email protected]>

drivers/pci/controller/dwc/pci-imx6.c

@@ -667,7 +667,6 @@ static int imx6_add_pcie_port(struct imx6_pcie *imx6_pcie,
 		}
 	}
 
-	pp->root_bus_nr = -1;
 	pp->ops = &imx6_pcie_host_ops;
 
 	ret = dw_pcie_host_init(pp);