riscv: ae350: dts: Add SPDX license header

The SPDX license header is currently missing. Add one.

Signed-off-by: Bin Meng <bmeng.cn@gmail.com>
Reviewed-by: Leo Yu-Chi Liang <ycliang@andestech.com>
Reviewed-by: Rick Chen <rick@andestech.com>
2 files changed