Make CLArithmeticSubtraction kernel and function state-less

Make CLArithmeticSubtraction kernel and function state-less

Resolves COMPMID-4008

Change-Id: Ic5f40610e771f31e6d301dfae976c81e9c79fa8b
Signed-off-by: Michele Di Giorgio <michele.digiorgio@arm.com>
Reviewed-on: https://review.mlplatform.org/c/ml/ComputeLibrary/+/4917
Reviewed-by: Michalis Spyrou <michalis.spyrou@arm.com>
Comments-Addressed: Arm Jenkins <bsgcomp@arm.com>
Tested-by: Arm Jenkins <bsgcomp@arm.com>