COMPMID-3957: Deprecate neon CV functions.

Change-Id: Idfc215c4f95472e2e61d2972cfd5d33786cc088e
Signed-off-by: morgolock <pablo.tello@arm.com>
Reviewed-on: https://review.mlplatform.org/c/ml/ComputeLibrary/+/4341
Comments-Addressed: Arm Jenkins <bsgcomp@arm.com>
Reviewed-by: Georgios Pinitas <georgios.pinitas@arm.com>
Reviewed-by: Sheri Zhang <sheri.zhang@arm.com>
Tested-by: Arm Jenkins <bsgcomp@arm.com>
diff --git a/arm_compute/runtime/NEON/functions/NESobel3x3.h b/arm_compute/runtime/NEON/functions/NESobel3x3.h
index a0b8f62..89a2e07 100644
--- a/arm_compute/runtime/NEON/functions/NESobel3x3.h
+++ b/arm_compute/runtime/NEON/functions/NESobel3x3.h
@@ -38,6 +38,8 @@
  * -# @ref NEFillBorderKernel (executed if border_mode == CONSTANT or border_mode == REPLICATE)
  * -# @ref NESobel3x3Kernel
  *
+ * @deprecated This function is deprecated and is intended to be removed in 21.05 release
+ *
  */
 class NESobel3x3 : public INESimpleFunction
 {