ggml-cuda: add chunked SSD matmul for Mamba-2 prefill acceleration (#22675)

ggml-cuda: add chunked SSD matmul for Mamba-2 prefill acceleration (#22675)

* ggml-cuda: add chunked SSD matmul for Mamba-2 prefill acceleration

* cuda: added SSD CICD fixes for CUDA / HIP / MUSA / MSVC.

* ggml-cuda: review comments fixed.

* ggml-cuda: Fuse M matrix materialization into pre_matmul kernel and enabled test.

* ggml-cuda: test updates and fixes

* ggml-cuda: test updates to remove hardcoding of tensor initialise data limits.

* ggml-cuda: ssd minor review comment fixed.

* ggml-cuda: ssd minor CICD fixed.

* CUDA SSD: Fixes correctness by promoting s0_stride_seq to int64_t, improves memory coalescing in ssm_ssd_prepare_dt_kernel, and boosts efficiency by merging B_weighted and C_scaled; also addresses prior review comments.

* cuda: fix sdata read-write race in prepare_dt fallback scan loop