Fix bug in PReluLayer when input is 1xN size

Fix issue where gpu elementwise operation kernel would not compile when
input is 1xN size and prelu is the chosen operator.

Add relevant tests for 1xN input.

Signed-off-by: Freddie Liardet <frederick.liardet@arm.com>
Change-Id: If0651cfa399ca1d9c65f2632b75536c7931f27d4
Reviewed-on: https://review.mlplatform.org/c/ml/ComputeLibrary/+/5760
Tested-by: Arm Jenkins <bsgcomp@arm.com>
Reviewed-by: Michele Di Giorgio <michele.digiorgio@arm.com>
Comments-Addressed: Arm Jenkins <bsgcomp@arm.com>
diff --git a/tests/validation/CL/PReluLayer.cpp b/tests/validation/CL/PReluLayer.cpp
index 82f3e4f..043262d 100644
--- a/tests/validation/CL/PReluLayer.cpp
+++ b/tests/validation/CL/PReluLayer.cpp
@@ -200,6 +200,11 @@
     // Validate output
     validate(CLAccessor(_target), _reference);
 }
+FIXTURE_DATA_TEST_CASE(RunOneDimensional, CLPReluLayerFixture<int16_t>, framework::DatasetMode::ALL, combine(framework::dataset::make("Shape", TensorShape(1U, 16U)), PReluLayerS16Dataset))
+{
+    // Validate output
+    validate(CLAccessor(_target), _reference);
+}
 TEST_SUITE_END()
 
 TEST_SUITE(Float)