Move WASM_ENABLE_SPEC_TEST to correct place (#1447)
Move WASM_ENABLE_SPEC_TEST to correct place (#1447)

Fix compilation warning:
```
wamr/product-mini/platforms/nuttx/../posix/main.c:622:5: warning: "WASM_ENABLE_SPEC_TEST" is not defined, evaluates to 0 [-Wundef]
  622 | #if WASM_ENABLE_SPEC_TEST != 0
```

Signed-off-by: Huang Qi <d5ddc73b08badd4d7d9ae5463eeb895d1f50627d@xiaomi.com>
bytecodealliance/wasm-micro-runtime,bytecodealliance/wasm-micro-runtime,bytecodealliance/wasm-micro-runtime,bytecodealliance/wasm-micro-runtime,bytecodealliance/wasm-micro-runtime,bytecodealliance/wasm-micro-runtime,bytecodealliance/wasm-micro-runtime,bytecodealliance/wasm-micro-runtime