[Minor] Simplify duplicative device check for cuda (#24793)

Signed-off-by: Ziliang Peng <ziliangdotme@gmail.com>

vllm/platforms/cuda.py

@@ -64,8 +64,7 @@ class CudaPlatformBase(Platform):
         if self.has_device_capability(80):
             # Ampere and Hopper or later NVIDIA GPUs.
             return [torch.bfloat16, torch.float16, torch.float32]
-        elif (not self.has_device_capability(80)
-              ) and self.has_device_capability(60):
+        if self.has_device_capability(60):
             # Pascal, Volta and Turing NVIDIA GPUs, BF16 is not supported
             return [torch.float16, torch.float32]
         # Kepler and Maxwell NVIDIA GPUs, only FP32 is supported,