Break up cutlass_extensions.cu, pt1 (#2944)

Summary:
X-link: facebookresearch/FBGEMM#47

Pull Request resolved: #2944

- Break up cutlass_extensions.cu

Before - https://www.internalfb.com/buck2/86b77fae-04e1-44ca-b13f-d946417d6135: 8:14.5s

Differential Revision: D60874248

fbgemm_gpu/experimental/gen_ai/CMakeLists.txt

@@ -15,6 +15,7 @@ set(fbgemm_sources_include_directories
   ${CMAKE_CURRENT_SOURCE_DIR}/../..
   ${CMAKE_CURRENT_SOURCE_DIR}/../../include
   ${CMAKE_CURRENT_SOURCE_DIR}/../../../include
+  ${CMAKE_CURRENT_SOURCE_DIR}/src/quantize
   # PyTorch
   ${TORCH_INCLUDE_DIRS}
   # Third-party
@@ -31,6 +32,8 @@ set(attention_ops_sources
 
 set(quantize_ops_sources
     src/quantize/cutlass_extensions.cu
+    src/quantize/cutlass_extensions/i8i8bf16.cu
+    src/quantize/cutlass_extensions/i8i8bf16_dynamic.cu
     src/quantize/quantize.cu
     src/quantize/quantize.cpp)