board: rockchip: Add support for rk3588s based Cool Pi 4B

CoolPi 4B is a rk3588s based SBC.

Specification:
- Rockchip RK3588S
- LPDDR4 2/4/8/16 GB
- TF scard slot
- eMMC 8/32/64/128 GB module
- SPI Nor 8MB
- Gigabit ethernet drived by PCIE with RTL8111HS
- HDMI Type D out
- Mini DP out
- USB 2.0 Host x 2
- USB 3.0 OTG x 1
- USB 3.0 Host x 1
- WIFI/BT module AIC8800
- 40 pin header

The dts is from linux-6.8 rc1.

Signed-off-by: Andy Yan <andyshrk@163.com>
Reviewed-by: Kever Yang <kever.yang@rock-chips.com>
[0]https://patchwork.kernel.org/project/linux-rockchip/patch/2450634.jE0xQCEvom@phil/
diff --git a/board/rockchip/evb_rk3588/MAINTAINERS b/board/rockchip/evb_rk3588/MAINTAINERS
index 2bd44bc..1604229 100644
--- a/board/rockchip/evb_rk3588/MAINTAINERS
+++ b/board/rockchip/evb_rk3588/MAINTAINERS
@@ -1,3 +1,10 @@
+COOLPI-4B-RK3588S
+M:	Andy Yan <andyshrk@163.com>
+S:	Maintained
+F:	configs/coolpi-4b-rk3588s_defconfig
+F:	arch/arm/dts/rk3588s-coolpi-4b.dts
+F:	arch/arm/dts/rk3588s-coolpi-u-boot.dtsi
+
 EVB-RK3588
 M:	Kever Yang <kever.yang@rock-chips.com>
 S:	Maintained