COMPMID-2959: Update NE/CL Permute documentation.

Clarify that any permutation vector is supported by NE/CL Permute as
long as its rank is not greater that 4

Change-Id: I4d2761f76131277d331b2f8bd69bd6dc3a2bb30d
Signed-off-by: Georgios Pinitas <georgios.pinitas@arm.com>
Reviewed-on: https://review.mlplatform.org/c/2417
Reviewed-by: Michele Di Giorgio <michele.digiorgio@arm.com>
Comments-Addressed: Arm Jenkins <bsgcomp@arm.com>
Tested-by: Arm Jenkins <bsgcomp@arm.com>
diff --git a/arm_compute/runtime/CL/functions/CLPermute.h b/arm_compute/runtime/CL/functions/CLPermute.h
index 322c472..40d9b63 100644
--- a/arm_compute/runtime/CL/functions/CLPermute.h
+++ b/arm_compute/runtime/CL/functions/CLPermute.h
@@ -39,6 +39,8 @@
 public:
     /** Set the input and output tensors.
      *
+     * @note Arbitrary permutation vectors are supported with rank not greater than 4
+     *
      * @param[in] input  The input tensor to permute. Data types supported: U8/S8/QASYMM8/U16/S16/F16/U32/S32/F32
      * @param[in] output The output tensor. Data types supported: Same as @p input
      * @param[in] perm   Permutation vector
@@ -46,6 +48,8 @@
     void configure(const ICLTensor *input, ICLTensor *output, const PermutationVector &perm);
     /**  Static function to check if given info will lead to a valid configuration of @ref CLPermute.
      *
+     * @note Arbitrary permutation vectors are supported with rank not greater than 4
+     *
      * @param[in] input  First tensor input info. Data types supported: U8/S8/QASYMM8/U16/S16/F16/U32/S32/F32.
      * @param[in] output Output tensor info. Data types supported: same as @p input.
      * @param[in] perm   Permutation vector