[ONCPUML-1451] Guard bf16 to bf16 tests with ARM_COMPUTE_ENABLE_FIXED_FORMAT_KERNELS

Change-Id: I6a01fe1e19a9d3e38908309d766fe7fc43775490
Signed-off-by: Renato Arantes <renato.arantes@arm.com>
Reviewed-on: https://review.mlplatform.org/c/ml/ComputeLibrary/+/11338
Benchmark: Arm Jenkins <bsgcomp@arm.com>
Tested-by: Arm Jenkins <bsgcomp@arm.com>
Reviewed-by: Gunes Bayir <gunes.bayir@arm.com>
diff --git a/tests/validation/NEON/MatMul.cpp b/tests/validation/NEON/MatMul.cpp
index 02f0bfd..f22bd9e 100644
--- a/tests/validation/NEON/MatMul.cpp
+++ b/tests/validation/NEON/MatMul.cpp
@@ -221,6 +221,7 @@
     validate(Accessor(_target), _reference, tolerance_bf16);
 }
 
+#ifdef ARM_COMPUTE_ENABLE_FIXED_FORMAT_KERNELS
 FIXTURE_DATA_TEST_CASE(RunTinyFixedFormat,
                        NEMatMulFixedFormatFixture<bfloat16>,
                        framework::DatasetMode::PRECOMMIT,
@@ -241,6 +242,7 @@
         validate(Accessor(_target), _reference, tolerance_bf16);
     }
 }
+#endif /* ARM_COMPUTE_ENABLE_FIXED_FORMAT_KERNELS */
 
 FIXTURE_DATA_TEST_CASE(RunLarge,
                        NEMatMulFastMathFixture<float>,