ggml : update `ggml_rope_multi` (#12665) * update `rope_multi`: 1. add `ggml_rope_multi_inplace`; 1. use `GGML_MROPE_SECTIONS` instead of 4. * Apply suggestions from code review Co-authored-by: Georgi Gerganov <ggerganov@gmail.com> --------- Co-authored-by: Georgi Gerganov <ggerganov@gmail.com>