ggml : add loongarch lsx and lasx support (#6454)
* add loongarch lsx and lasx optimize code
* Add loongarch compilation support to makefile
* revert stb_image.h
* opt bytes_from_nibbles_32 and sum_i16_pairs_float
* fix undeclared
* format code
* update
* update 2
---------
Co-authored-by: Jinyang He <hejinyang@loongson.cn>