huashan: cleanup: move hw_config into rootdir and completely remove existence of prebuits dir

Change-Id: Ib73cf33fdba9c3f1d72b9e8a1be793bad75d5874
Signed-off-by: Arnav Gupta <championswimmer@aokp.co>
Merge "huashan: cleanup: move hw_config into rootdir and completely remove existence of prebuits dir" into kitkat