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

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Co-authored-by: Jinyang He <hejinyang@loongson.cn>