llama : add phi-2 + fix NeoX rope + ggml_mul_mat_set_prec (#4490)

llama : add phi-2 + fix NeoX rope + ggml_mul_mat_set_prec (#4490)

* phi2 implementation

* fix breaking change

* phi-2 : various fixes

* phi-2 : use layer norm eps

* py : whitespaces

* llama : fix meta KV override bug

* convert : phi don't add BOS token

* convert : revert "added_tokens_decoder" change

* phi-2 : scale Q instead of KQ for better precision

* ggml : fix NeoX rope to rotate just first n_dims

* cuda : less diff in the rope_neox kernel

* ggml : add ggml_mul_mat_set_prec

ggml-ci

* Update ggml-cuda.cu

Co-authored-by: slaren <redacted>
* Update ggml-cuda.cu

Co-authored-by: slaren <redacted>
* cuda : ggml_cuda_op_mul_mat_cublas support F32 precision

* cuda : remove oboslete comment

---------

Co-authored-by: Ebey Abraham <redacted>
Co-authored-by: Georgi Gerganov <redacted>
Co-authored-by: slaren <redacted>