[Kernel] Split Marlin MoE kernels into multiple files (#8661)

Co-authored-by: mgoin <[email protected]>

Author: ElizaWszola

CMakeLists.txt

@@ -316,6 +316,11 @@ set(VLLM_MOE_EXT_SRC
 
 if(VLLM_GPU_LANG STREQUAL "CUDA")
   list(APPEND VLLM_MOE_EXT_SRC
+      "csrc/moe/marlin_kernels/marlin_moe_kernel.h"
+      "csrc/moe/marlin_kernels/marlin_moe_kernel_ku4b8.h"
+      "csrc/moe/marlin_kernels/marlin_moe_kernel_ku4b8.cu"
+      "csrc/moe/marlin_kernels/marlin_moe_kernel_ku8b128.h"
+      "csrc/moe/marlin_kernels/marlin_moe_kernel_ku8b128.cu"
       "csrc/moe/marlin_moe_ops.cu")
 endif()