ggml : add RISC-V Vector Support for K-Quants and improved the existing intrinsics...

ggml : add RISC-V Vector Support for K-Quants and improved the existing intrinsics (#3453)

* Added RVV intrinsics support for Q8 quantize row and also improved the existing dot product function for risc-v.

The RVV intrinsics is added for the following quantize row functions
   quantize_row_q8_0
   quantize_row_q8_1

The following dot product functions have also been optimized by using LMUL = 1/2 instead of LMUL = 1
   ggml_vec_dot_q4_0_q8_0
   ggml_vec_dot_q4_1_q8_1
   ggml_vec_dot_q5_0_q8_0
   ggml_vec_dot_q5_1_q8_1

And vector initialization in Q5 by temporary array is also replaced by the vid intrinsics

Signed-off-by: Ahmad Tameem <redacted>
* Added RVV intrinsics support for k_quants

This adds RISC-V Vector intrinsics support for the following K_quants functions for both QKK = 256 and QKK = 64
   ggml_vec_dot_q2_K_q8_K
   ggml_vec_dot_q3_K_q8_K
   ggml_vec_dot_q4_K_q8_K
   ggml_vec_dot_q5_K_q8_K
   ggml_vec_dot_q6_K_q8_K

Signed-off-by: Ahmad Tameem <redacted>
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Signed-off-by: Ahmad Tameem <redacted>