COMPMID-4025 [Nightly failure] Fix FP16 CLWidthConcatenateLayer mismatches

COMPMID-4025 [Nightly failure] Fix FP16 CLWidthConcatenateLayer mismatches

Change-Id: I62e09682fe42c17227208387135ff2a165357335
Signed-off-by: Giorgio Arena <giorgio.arena@arm.com>
Reviewed-on: https://review.mlplatform.org/c/ml/ComputeLibrary/+/4553
Reviewed-by: Pablo Marquez Tello <pablo.tello@arm.com>
Tested-by: Arm Jenkins <bsgcomp@arm.com>
Comments-Addressed: Arm Jenkins <bsgcomp@arm.com>
(cherry picked from commit c90fcfe90721ecc4cf1045b60bf1c933cb4823f6)
Reviewed-on: https://review.mlplatform.org/c/ml/ComputeLibrary/+/4177
Tested-by: Michele Di Giorgio <michele.digiorgio@arm.com>