MLECO-4374 Fix ITCM overflow issues flagged by CI

Change-Id: Ic34b01af1a7e763b92ade52a4833201d4287ec60
Reviewed-on: https://eu-gerrit-2.euhpc.arm.com/c/ml/ecosystem/ml-embedded-evaluation-kit/+/775365


Tested-by: mlecosys <mlecosys@arm.com>
Reviewed-by: Conor Kennedy <conor.kennedy@arm.com>
Reviewed-by: Richard Burton <richard.burton@arm.com>