[perf][cpu] Accelerate paged attention GEMMs (QK, PV) on Arm CPUs with NEON (#29193)

Signed-off-by: Fadi Arafeh <fadi.arafeh@arm.com>

vllm/engine/arg_utils.py

@@ -1392,11 +1392,10 @@ class EngineArgs:
         # Set default arguments for V1 Engine.
         self._set_default_args(usage_context, model_config)
         # Disable chunked prefill and prefix caching for:
-        # POWER (ppc64le)/ARM/s390x/RISCV CPUs in V1
+        # POWER (ppc64le)/s390x/RISCV CPUs in V1
         if current_platform.is_cpu() and current_platform.get_cpu_architecture() in (
             CpuArchEnum.POWERPC,
             CpuArchEnum.S390X,
-            CpuArchEnum.ARM,
             CpuArchEnum.RISCV,
         ):
             logger.info(