soc: andestech: soc_per_core_init_hook() shouldn't return value

The `soc_per_core_init_hook()` function now has `void` type after
da118b9f, so it should just return without any value.

Signed-off-by: Yong Cong Sin <ycsin@meta.com>
Signed-off-by: Yong Cong Sin <yongcong.sin@gmail.com>