Update config.json

from vLLM logic:
per block intermediate size = int(2 * ffn_mult * n_embd / 3)
2 * 5.25 * 8192 / 2 = 43008

ceiling to nearest 512: n + k - (n % k)
43008 + 512 - (43008 % 512)
= 43520

config.json

@@ -1455,7 +1455,7 @@
   "hidden_act": "silu",
   "hidden_size": 8192,
   "initializer_range": 0.02,
-  "intermediate_size": null,
+  "intermediate_size": 43520,
   "max_position_embeddings": 131072,
   "mlp_bias": false,
   "model_type": "nemotron-nas",