pci: Honour pci_skip_dev()

When enumerating devices, honour the pci_skip_dev() function. This can
be used by PCI controller drivers to restrict which devices will be
probed.

This is required by the NVIDIA Tegra PCIe controller driver, which will
fail with a data abort exception if an access is attempted to a device
number larger than 0 outside of bus 0. pci_skip_dev() is therefore
implemented to prevent any such accesses.

Signed-off-by: Thierry Reding <treding@nvidia.com>
Signed-off-by: Simon Glass <sjg@chromium.org>
diff --git a/common/cmd_pci.c b/common/cmd_pci.c
index 5a6048c..e3a77e3 100644
--- a/common/cmd_pci.c
+++ b/common/cmd_pci.c
@@ -71,6 +71,9 @@
 
 			dev = PCI_BDF(BusNum, Device, Function);
 
+			if (pci_skip_dev(hose, dev))
+				continue;
+
 			pci_read_config_word(dev, PCI_VENDOR_ID, &VendorID);
 			if ((VendorID == 0xFFFF) || (VendorID == 0x0000))
 				continue;