build : support ppc64le build for make and CMake (#3963)
* build: support ppc64le build for make and CMake
* build: keep __POWER9_VECTOR__ ifdef and extend with __powerpc64__
Co-authored-by: Georgi Gerganov <ggerganov@gmail.com>
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Co-authored-by: Georgi Gerganov <ggerganov@gmail.com>