[ET-VK] Replace uint16_t with int for swiftshader

As title. This is a follow up from #6675. Replace `uint16_t` with `int` as well as 16 bit vectorized types.

Differential Revision: [D65824204](https://our.internmc.facebook.com/intern/diff/D65824204/)

ghstack-source-id: 253112193
Pull Request resolved: #6781

Author: SS-JIA

backends/vulkan/runtime/gen_vulkan_spv.py

@@ -721,6 +721,7 @@ def maybe_replace_u16vecn(self, input_text: str) -> str:
             return input_text
 
         input_text = input_text.replace("u16vec", "ivec")
+        input_text = input_text.replace("uint16_t", "int")
         return input_text
 
     def generateSPV(self, output_dir: str) -> Dict[str, str]: