pci: Add Rockchip dwc based PCIe controller driver

Add Rockchip dwc based PCIe controller driver for rk356x platform.
Driver support Gen3 by operating as a Root complex.

Signed-off-by: Shawn Lin <shawn.lin@rock-chips.com>
Reviewed-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Kever Yang<kever.yang@rock-chips.com>
diff --git a/drivers/pci/Kconfig b/drivers/pci/Kconfig
index 65498bc..b1de38f 100644
--- a/drivers/pci/Kconfig
+++ b/drivers/pci/Kconfig
@@ -281,6 +281,15 @@
 	  Say Y here if you want to enable PCIe controller support on
 	  Rockchip SoCs.
 
+config PCIE_DW_ROCKCHIP
+	bool "Rockchip DesignWare based PCIe controller"
+	depends on ARCH_ROCKCHIP
+	select DM_PCI
+	select PHY_ROCKCHIP_SNPS_PCIE3
+	help
+	  Say Y here if you want to enable DW PCIe controller support on
+	  Rockchip SoCs.
+
 config PCI_BRCMSTB
 	bool "Broadcom STB PCIe controller"
 	depends on DM_PCI