PCI: imx6: Allow asynchronous probing

Establishing a PCIe link can take a while; allow asynchronous probing so
that link establishment can happen in the background while other devices
are being probed.
Signed-off-by: NLucas Stach <l.stach@pengutronix.de>
Signed-off-by: NLorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Signed-off-by: NBjorn Helgaas <bhelgaas@google.com>
Reviewed-by: NFabio Estevam <festevam@gmail.com>

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

@@ -1279,6 +1279,7 @@ static struct platform_driver imx6_pcie_driver = {
 		.of_match_table = imx6_pcie_of_match,
 		.suppress_bind_attrs = true,
 		.pm = &imx6_pcie_pm_ops,
+		.probe_type = PROBE_PREFER_ASYNCHRONOUS,
 	},
 	.probe    = imx6_pcie_probe,
 	.shutdown = imx6_pcie_shutdown,