PCI: brcmstb: Fix potential premature regluator disabling

Our system for enabling and disabling regulators is designed to work
only on the port driver below the root complex.  The conditions to
discriminate for this case should be the same when we are adding or
removing the bus.  Without this change the regulators may be disabled
prematurely when a bus further down the tree is removed.

Fixes: 9e6be01 ("PCI: brcmstb: Enable child bus device regulators from DT")
Signed-off-by: Jim Quinlan <james.quinlan@broadcom.com>

Author: jamesequinlan

drivers/pci/controller/pcie-brcmstb.c

@@ -1441,7 +1441,7 @@ static void brcm_pcie_remove_bus(struct pci_bus *bus)
 	struct subdev_regulators *sr = pcie->sr;
 	struct device *dev = &bus->dev;
 
-	if (!sr)
+	if (!sr || !bus->parent || !pci_is_root_bus(bus->parent))
 		return;
 
 	if (regulator_bulk_disable(sr->num_supplies, sr->supplies))