* ggml: dynamic x86_64 feature detection for FP32 <-> FP16/BF16 conversion * move fp converter to ggml-cpu * Switch ggml_compute_forward_get_rows_f16/bf16 to new ggml_cpu_fp16/bf16_to_fp32
* ggml: use _mm[512/256]_dpbusd[_avx]_epi32 to directly accumulate into the result register * simplifies the codebase by removing redundant functions