board: rockchip: Add Hardkernel ODROID-M2

The Hardkernel ODROID-M2 is a single-board computer based on Rockchip
RK3588S2 SoC. It features e.g. 8/16 GB LPDDR5 RAM, 64 GB eMMC, SD-card,
GbE LAN, HDMI 2.0, M.2 NVMe and USB 2.0/3.0/Type-C.

Features tested on a ODROID-M2 16GB rev1.0 20240611:
- SD-card boot
- eMMC boot
- Ethernet
- PCIe/NVMe
- USB gadget
- USB host

Signed-off-by: Jonas Karlman <jonas@kwiboo.se>
Reviewed-by: Kever Yang <kever.yang@rock-chips.com>
diff --git a/doc/board/rockchip/rockchip.rst b/doc/board/rockchip/rockchip.rst
index 86d83be..a50e3d2 100644
--- a/doc/board/rockchip/rockchip.rst
+++ b/doc/board/rockchip/rockchip.rst
@@ -132,6 +132,7 @@
      - FriendlyElec NanoPi R6C (nanopi-r6c-rk3588s)
      - FriendlyElec NanoPi R6S (nanopi-r6s-rk3588s)
      - Generic RK3588S/RK3588 (generic-rk3588)
+     - Hardkernel ODROID-M2 (odroid-m2-rk3588s)
      - Indiedroid Nova (nova-rk3588s)
      - Pine64 QuartzPro64 (quartzpro64-rk3588)
      - Radxa ROCK 5 ITX (rock-5-itx-rk3588)