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/include/dm/uclass-id.h b/include/dm/uclass-id.h
index 4183928..5056a08 100644
--- a/include/dm/uclass-id.h
+++ b/include/dm/uclass-id.h
@@ -69,6 +69,7 @@
 	UCLASS_PANEL_BACKLIGHT,	/* Backlight controller for panel */
 	UCLASS_PCH,		/* x86 platform controller hub */
 	UCLASS_PCI,		/* PCI bus */
+	UCLASS_PCI_EP,		/* PCI endpoint device */
 	UCLASS_PCI_GENERIC,	/* Generic PCI bus device */
 	UCLASS_PHY,		/* Physical Layer (PHY) device */
 	UCLASS_PINCONFIG,	/* Pin configuration node device */