COMPMID-2753: Add support for QASYMM8_SIGNED in CL kernels/functions

Change-Id: I7ed2d43f33458ba0571323f6fa9dc2e45fcd672a
Signed-off-by: Manuel Bottini <manuel.bottini@arm.com>
Reviewed-on: https://review.mlplatform.org/c/2516
Comments-Addressed: Arm Jenkins <bsgcomp@arm.com>
Reviewed-by: Michele Di Giorgio <michele.digiorgio@arm.com>
Tested-by: Arm Jenkins <bsgcomp@arm.com>
Reviewed-by: Georgios Pinitas <georgios.pinitas@arm.com>
diff --git a/arm_compute/runtime/CL/functions/CLFlattenLayer.h b/arm_compute/runtime/CL/functions/CLFlattenLayer.h
index 9597cd2..b9ce236 100644
--- a/arm_compute/runtime/CL/functions/CLFlattenLayer.h
+++ b/arm_compute/runtime/CL/functions/CLFlattenLayer.h
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2017-2019 ARM Limited.
+ * Copyright (c) 2017-2020 ARM Limited.
  *
  * SPDX-License-Identifier: MIT
  *
@@ -42,7 +42,7 @@
     /** Initialise the kernel's input and output.
      *
      * @param[in]  input  First input tensor to flatten with at least 3 dimensions.
-     *                    The dimensions above the third will be interpreted as batches. Data types supported: U8/S8/QASYMM8/U16/S16/F16/U32/S32/F32
+     *                    The dimensions above the third will be interpreted as batches. Data types supported: All.
      * @param[out] output Output tensor with shape [w*h*d, input_batches] where:
      *                    w = width input tensor, h = height input tensor and d = depth input tensor. Data type supported: same as @p input
      */
@@ -50,7 +50,7 @@
     /** Static function to check if given info will lead to a valid configuration of @ref CLFlattenLayer
      *
      * @param[in]  input  First input tensor to flatten with at least 3 dimensions.
-     *                    The dimensions above the third will be interpreted as batches. Data types supported: U8/S8/QASYMM8/U16/S16/F16/U32/S32/F32
+     *                    The dimensions above the third will be interpreted as batches. Data types supported: All.
      * @param[out] output Output tensor with shape [w*h*d, input_batches] where:
      *                    w = width input tensor, h = height input tensor and d = depth input tensor. Data type supported: same as @p input
      *