[CPU] Fix torch version in x86 CPU backend (#19258)

Signed-off-by: jiang1.li <jiang1.li@intel.com>

tests/models/multimodal/generation/test_common.py

@@ -107,6 +107,8 @@ VLM_TEST_SETTINGS = {
             ),
             limit_mm_per_prompt={"image": 4},
         )],
+        # TODO: Revert to "auto" when CPU backend can use torch > 2.6
+        dtype="bfloat16" if current_platform.is_cpu() else "auto",
         marks=[pytest.mark.core_model, pytest.mark.cpu_model],
     ),
     "paligemma": VLMTestInfo(