ggml-hexagon: gelu optimization (#18151)

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

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Co-authored-by: Max Krasnyansky <redacted>