COMPMID-3532: Align data type support between doxygen and implementation - CL

Also removes some unused code.

Change-Id: I85687c40999c3cdf9e6fccfcd020b0901a9515fe
Signed-off-by: Michele Di Giorgio <michele.digiorgio@arm.com>
Reviewed-on: https://review.mlplatform.org/c/ml/ComputeLibrary/+/3581
Reviewed-by: Georgios Pinitas <georgios.pinitas@arm.com>
Comments-Addressed: Arm Jenkins <bsgcomp@arm.com>
Tested-by: Arm Jenkins <bsgcomp@arm.com>
diff --git a/src/core/CL/cl_kernels/nonmax.cl b/src/core/CL/cl_kernels/nonmax.cl
index e618b0a..ab13131 100644
--- a/src/core/CL/cl_kernels/nonmax.cl
+++ b/src/core/CL/cl_kernels/nonmax.cl
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2016, 2017 Arm Limited.
+ * Copyright (c) 2016-2020 Arm Limited.
  *
  * SPDX-License-Identifier: MIT
  *
@@ -25,13 +25,13 @@
 
 /** This function performs Non maxima suppression over a 3x3 window on a given image.
  *
- * @param[in]  src_ptr                           Pointer to the source image. Supported data types: F32
+ * @param[in]  src_ptr                           Pointer to the source image. Supported data types: U8/F32
  * @param[in]  src_stride_x                      Stride of the source image in X dimension (in bytes)
  * @param[in]  src_step_x                        src_stride_x * number of elements along X processed per workitem(in bytes)
  * @param[in]  src_stride_y                      Stride of the source image in Y dimension (in bytes)
  * @param[in]  src_step_y                        src_stride_y * number of elements along Y processed per workitem(in bytes)
  * @param[in]  src_offset_first_element_in_bytes The offset of the first element in the source image
- * @param[out] dst_ptr                           Pointer to the destination image. Supported data types: F32
+ * @param[out] dst_ptr                           Pointer to the destination image. Supported data types: same as @p scr_ptr
  * @param[in]  dst_stride_x                      Stride of the destination image in X dimension (in bytes)
  * @param[in]  dst_step_x                        dst_stride_x * number of elements along X processed per workitem(in bytes)
  * @param[in]  dst_stride_y                      Stride of the destination image in Y dimension (in bytes)