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>
diff --git a/src/core/gpu/cl/kernels/ClWidthConcatenate2TensorsKernel.h b/src/core/gpu/cl/kernels/ClWidthConcatenate2TensorsKernel.h
index 9271500..ddade29 100644
--- a/src/core/gpu/cl/kernels/ClWidthConcatenate2TensorsKernel.h
+++ b/src/core/gpu/cl/kernels/ClWidthConcatenate2TensorsKernel.h
@@ -46,9 +46,9 @@
     /** Initialise the kernel's sources and destination
      *
      * @param[in]  compile_context The compile context to be used.
-     * @param[in]  src1            First source tensor. Data types supported: All.
-     * @param[in]  src2            Second source tensor. Data types supported: same as @p src1
-     * @param[out] dst             Destination tensor. Data types supported: Same as @p src1.
+     * @param[in]  src1            First source tensor info. Data types supported: All.
+     * @param[in]  src2            Second source tensor info. Data types supported: same as @p src1
+     * @param[out] dst             Destination tensor info. Data types supported: Same as @p src1.
      */
     void configure(const CLCompileContext &compile_context, ITensorInfo *src1, ITensorInfo *src2, ITensorInfo *dst);
     /**  Static function to check if given info will lead to a valid configuration of @ref ClWidthConcatenate2TensorsKernel