rockchip: Add initial support for the PINE64 Pinephone Pro

The Pinephone Pro is another device by PINE64. It's closely related
to the Pinebook Pro of which this initial support is derived from.

Specification:
- A variant of the Rockchip RK3399
- A 6 inch 720*1440 DSI display
- Front and rear cameras
- Type-C interface with alt mode display (DP 1.2) and PD charging
- 4GB LPDDR4 RAM
- 128GB eMMC
- mSD card slot
- An AP6255 module for 802.11ac WiFi and Bluetooth 5
- Quectel EG25-G 4G/LTE modem

Signed-off-by: Peter Robinson <pbrobinson@gmail.com>
Reviewed-by: Simon Glass <sjg@chromium.org>
diff --git a/arch/arm/mach-rockchip/rk3399/Kconfig b/arch/arm/mach-rockchip/rk3399/Kconfig
index b48feeb..d01063a 100644
--- a/arch/arm/mach-rockchip/rk3399/Kconfig
+++ b/arch/arm/mach-rockchip/rk3399/Kconfig
@@ -39,6 +39,13 @@
 	  with 4Gb RAM, onboard eMMC, USB-C, a USB3 and USB2 port,
 	  1920*1080 screen and all the usual laptop features.
 
+config TARGET_PINEPHONE_PRO_RK3399
+	bool "PinePhone Pro"
+	help
+	  PinePhone Pro is a phone based on a variant of the Rockchip
+	  rk3399 SoC with 4Gb RAM, onboard eMMC, USB-C, headphone jack,
+	  720x1440 screen and a Quectel 4G/LTE modem.
+
 config TARGET_PUMA_RK3399
 	bool "Theobroma Systems RK3399-Q7 (Puma)"
 	help
@@ -165,6 +172,7 @@
 source "board/firefly/roc-pc-rk3399/Kconfig"
 source "board/google/gru/Kconfig"
 source "board/pine64/pinebook-pro-rk3399/Kconfig"
+source "board/pine64/pinephone-pro-rk3399/Kconfig"
 source "board/pine64/rockpro64_rk3399/Kconfig"
 source "board/rockchip/evb_rk3399/Kconfig"
 source "board/theobroma-systems/puma_rk3399/Kconfig"