ggml-hexagon: gelu optimization (#18151)

* feat: working gelu with src0 put on vtcm

* feat: gelu ping-pong for both in and out

* fix: fixu compile error

* break: distinguish dma ddr->vtcm and vtcm->ddr operation

* fix: fix dma queue size

* break: update dma api to either pop src or dst ptr

* fix: fix activation vtcm allocation issue for src1 when swapperd

* refactor: ping-pong gelu logic to avoid unnecessary if else

* dma: improved queue interface and prefetch handling

* gelu: fix N+2 block prefetch

---------

Co-authored-by: Max Krasnyansky <maxk@qti.qualcomm.com>

ggml/src/ggml-hexagon/htp/main.c

@@ -299,7 +299,8 @@ AEEResult htp_iface_start(remote_handle64 handle, uint32 sess_id, uint64 dsp_que
 
     ctx->n_threads = n_hvx;
     for (int i = 0; i < ctx->n_threads; i++) {
-        ctx->dma[i] = dma_queue_create(HTP_SPAD_SRC0_NROWS * 2);
+        // see discussion https://github.com/ggml-org/llama.cpp/pull/18151#discussion_r2632388541
+        ctx->dma[i] = dma_queue_create(64);
     }
 
     // init worker pool