board: rockchip: Add support for rk3588 GenBook

Add support for Cool Pi GenBook, it works as a carrier board
connect with CM5 SOM.

Specification:
- Rockchip RK3588
- LPDDR5X 8/32 GB
- eMMC 64 GB
- HDMI Type A out x 1
- USB 3.0 Host x 1
- USB-C 3.0 with DisplayPort AltMode
- PCIE M.2 E Key for RTL8852BE Wireless connection
- PCIE M.2 M Key for NVME connection
- eDP panel with 1920x1080

Tested by Armbian boot on USB disk.

Change-Id: I4d9b8572dc7c400077dde666633f3fea1b47dd03
Signed-off-by: Andy Yan <andyshrk@163.com>
Reviewed-by: Kever Yang <kever.yang@rock-chips.com>
diff --git a/doc/board/rockchip/rockchip.rst b/doc/board/rockchip/rockchip.rst
index 0783603..3056e07 100644
--- a/doc/board/rockchip/rockchip.rst
+++ b/doc/board/rockchip/rockchip.rst
@@ -148,6 +148,7 @@
      - Xunlong Orange Pi 5 Plus (orangepi-5-plus-rk3588)
      - Yanyi Tech CoolPi 4 Model B (coolpi-4b-rk3588s)
      - Yanyi Tech CoolPi CM5 EVB (coolpi-cm5-evb-rk3588)
+     - Yanyi Tech CoolPi CM5 GenBook (coolpi-cm5-genbook-rk3588)
 
 * rv1108
      - Rockchip Evb-rv1108 (evb-rv1108)