Fused MoE ffn_up and ffn_gate (#229)

* Fusing MoE up * unary(gate)

* Fusing MoE up * unary(gate): CUDA

We get ~13% speedup for PP-512 and ~2% for TG-128
for DeepSeek-Lite

* On CUDA also fuse MoE down * (up * unary(gate))

in case the MUL_MAT_ID op for the down experts is the next
op in the graph.

* Command line option to enable fused MoE up*unary(gate)

* Add fmoe option to llama-bench

* Adding forgotten gelu, relu, silu on ARM

---------

Co-authored-by: Iwan Kawrakow <iwan.kawrakow@gmail.com>

include/llama.h

@@ -377,6 +377,7 @@ extern "C" {
         bool offload_kqv; // whether to offload the KQV ops (including the KV cache) to GPU
         bool flash_attn;  // whether to use flash attention [EXPERIMENTAL]
         bool mla_attn;    // whether to use MLA attention [EXPERIMENTAL]
+        bool fused_moe_up_gate; // whether to use fused MoE up/down op [EXPERIMENTAL]
 
         // Abort callback
         // if it returns true, execution of llama_decode() will be aborted