pci: Add Rockchip PCIe controller driver

Add Rockchip PCIe controller driver for rk3399 platform.

Driver support Gen1 by operating as a Root complex.

Thanks to Patrick for initial work.

Signed-off-by: Patrick Wildt <patrick@blueri.se>
Signed-off-by: Jagan Teki <jagan@amarulasolutions.com>
Reviewed-by: Kever Yang <kever.yang@rock-chips.com>
Tested-by: Suniel Mahesh <sunil@amarulasolutions.com> #roc-rk3399-pc
diff --git a/drivers/pci/Kconfig b/drivers/pci/Kconfig
index 6fc2688..6d8c22a 100644
--- a/drivers/pci/Kconfig
+++ b/drivers/pci/Kconfig
@@ -197,4 +197,12 @@
 	  Say Y here if you want to enable Gen2 PCIe controller,
 	  which could be found on MT7623 SoC family.
 
+config PCIE_ROCKCHIP
+	bool "Enable Rockchip PCIe driver"
+	select DM_PCI
+	default y if ROCKCHIP_RK3399
+	help
+	  Say Y here if you want to enable PCIe controller support on
+	  Rockchip SoCs.
+
 endif