riscv: dts: sophgo: add Sophgo SG2042_EVB_V2.0 board device tree

riscv: dts: sophgo: add Sophgo SG2042_EVB_V2.0 board device tree

Sophgo SG2042_EVB_V2.0 [1] is a prototype development board based on SG2042

Currently supports serial port, sdcard/emmc, pwm, fan speed control.

Link: https://github.com/sophgo/sophgo-hardware/tree/master/SG2042/SG2042-x4-EVB
Signed-off-by: Han Gao <rabenda.cn@gmail.com>
Reviewed-by: Nutty Liu <liujingqi@lanxincomputing.com>
Reviewed-by: Chen Wang <unicorn_wang@outlook.com>
Link: https://lore.kernel.org/r/c1b6ccdc69af0c1457fc1486a6bc8a1e83671537.1751700954.git.rabenda.cn@gmail.com
Signed-off-by: Inochi Amaoto <inochiama@gmail.com>
Signed-off-by: Chen Wang <unicorn_wang@outlook.com>
Signed-off-by: Chen Wang <wangchen20@iscas.ac.cn>