drivers: pci_ep: Introduce UCLASS_PCI_EP uclass

Introduce new UCLASS_PCI_EP class for handling PCI endpoint
devices, allowing to set various attributes of the PCI endpoint
device, such as:
* configuration space header
* BAR definitions
* outband memory mapping
* start/stop PCI link

Signed-off-by: Ramon Fried <ramon.fried@gmail.com>
Reviewed-by: Simon Glass <sjg@chromium.org>
diff --git a/drivers/pci_endpoint/Makefile b/drivers/pci_endpoint/Makefile
new file mode 100644
index 0000000..80a1066
--- /dev/null
+++ b/drivers/pci_endpoint/Makefile
@@ -0,0 +1,6 @@
+# SPDX-License-Identifier: GPL-2.0+
+#
+# (C) Copyright 2019
+# Ramon Fried <ramon.fried@gmail.com>
+
+obj-y += pci_ep-uclass.o