arm64: dts: rockchip: Add support for Khadas Edge-Captain

Add devicetree support for Khadas Edge-Captain.
Khadas Captain is the carrier board for Khadas Edge.

Specification
- Rockchip RK3399
- Dual-Channel 2GB/4GB LPDDR4
- SD card slot
- Onboard 16GB/32GB/128GB eMMC
- RTL8211FD 1Gbps
- AP6356S/AP6398S WiFI/BT
- HDMI Out, DP, MIPI DSI/CSI, eDP
- USB 3.0, 2.0
- USB Type C power and data
- GPIO expansion ports
- Full 4 Lane M.2 Socket
- 16MB SPI Flash
- IR
- Programmable MCU

Commit details of rk3399-khadas-edge-*.dts sync from Linux 5.3-rc2:
"arm64: dts: rockchip: Add support for Khadas Edge/Edge-V/Captain boards"
(sha1: c2aacceedc86af87428d998e23a1aca24fd8aa2e)

Signed-off-by: Nick Xie <nick@khadas.com>
Tested-by: Chris Webb <chris@arachsys.com>
Reviewed-by: Kever Yang <kever.yang@rock-chips.com>
diff --git a/arch/arm/dts/rk3399-khadas-edge-captain-u-boot.dtsi b/arch/arm/dts/rk3399-khadas-edge-captain-u-boot.dtsi
new file mode 100644
index 0000000..ca1bbff
--- /dev/null
+++ b/arch/arm/dts/rk3399-khadas-edge-captain-u-boot.dtsi
@@ -0,0 +1,6 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Copyright (C) 2019 Nick Xie <nick@khadas.com>
+ */
+
+#include "rk3399-khadas-edge-u-boot.dtsi"