issues about YaRN

[foldl]

I am using YaRN when implementing DeepSeek V2 models. And current YaRN does not look good me.

@cebtenzzre Could you take a look on this? Correct me if I am wrong.

1. theta_base *= freq_scale is done again later in rope_yarn:

   ggml/src/ggml.c

   Line 14077 in 0cbb7c0

   theta_base *= freq_scale;

   In a basic case (ext_factor is 0), the theta uses for cos/sin is scaled by freq_scale * freq_scale. I think this is wrong and this line should be deleted.

2. value passed to int64_t i0 is wrong: (data type does not matches, either.)

   ggml/src/ggml.c

   Lines 14082 to 14088 in 0cbb7c0

   	// simplified from `(ib * n_dims + ic) * inv_ndims`
   	float cur_rot = inv_ndims * ic - ib;
   	float cos_theta, sin_theta;
   	rope_yarn(
   	theta_base, freq_scale, corr_dims, cur_rot, ext_factor, attn_factor,
   	&cos_theta, &sin_theta

   I think it should be ic here.

   (Confirmed when implementing DeepSeek V2 models)