rockchip: Enable PCIe/M.2 on rk3399 board w/ M.2

Enable PCIe/M.2 support on
- NanoPC-T4
- ROC-RK3399-PC Mezzanine boards.

Signed-off-by: Jagan Teki <jagan@amarulasolutions.com>
Tested-by: Suniel Mahesh <sunil@amarulasolutions.com> #roc-rk3399-pc
Reviewed-by: Kever Yang <kever.yang@rock-chips.com>
diff --git a/arch/arm/dts/rk3399-u-boot.dtsi b/arch/arm/dts/rk3399-u-boot.dtsi
index 22017ec..8237782 100644
--- a/arch/arm/dts/rk3399-u-boot.dtsi
+++ b/arch/arm/dts/rk3399-u-boot.dtsi
@@ -8,6 +8,7 @@
 	aliases {
 		mmc0 = &sdhci;
 		mmc1 = &sdmmc;
+		pci0 = &pcie0;
 	};
 
 	cic: syscon@ff620000 {