[Refactor] Replace activation: str with MoEActivation enum (#33843)

Signed-off-by: mgoin <mgoin64@gmail.com>
Signed-off-by: Michael Goin <mgoin64@gmail.com>

tests/kernels/moe/test_cpu_fused_moe.py

@@ -6,6 +6,7 @@ import torch
 
 from tests.kernels.allclose_default import get_default_atol, get_default_rtol
 from vllm._custom_ops import cpu_fused_moe, cpu_prepack_moe_weight
+from vllm.model_executor.layers.fused_moe.activation import MoEActivation
 from vllm.model_executor.layers.fused_moe.cpu_fused_moe import _CPU_MOE_ACT_FN
 from vllm.platforms import current_platform
 from vllm.utils.torch_utils import set_random_seed
@@ -19,7 +20,7 @@ EXPERT_NUM = [
 HIDDEN_DIM = [128, 2880]
 INTERMEDIATE_DIM = [128, 2880]
 BATCH_SIZE = [1, 64, 256]
-ACT = ["silu", "swigluoai"]
+ACT = [MoEActivation.SILU, MoEActivation.SWIGLUOAI]
 USE_BIAS = [True, False]
 ISA = ["amx", "vec"] if torch._C._cpu._is_amx_tile_supported() else ["vec"]
 DTYPE = [torch.bfloat16]
@@ -33,7 +34,7 @@ def ref_fused_moe(
     w2_bias: torch.Tensor | None,
     topk_weights: torch.Tensor,
     topk_ids: torch.Tensor,
-    activation: str,
+    activation: MoEActivation,
 ) -> torch.Tensor:
     len_experts = w13.size(0)
 
@@ -103,7 +104,7 @@ def test_cpu_fused_moe(
     intermediate_size: int,
     use_bias: bool,
     dtype: torch.dtype,
-    act: str,
+    act: MoEActivation,
     isa: str,
 ):
     set_random_seed(0)
@@ -153,7 +154,7 @@ def test_cpu_fused_moe(
         w2_bias,
         topk_weight,
         topk_ids,
-        act,
+        act.value,
         isa,
     )