MLECO-2082 Fixes and improvements from OOB

  -Fixed noise_reduction CMake bug cause inference to fail when non-default mac_units passed to build script
  -Inference complete message added to noise_reduction LCD
  -Doc update clarfiy vela.ini config file for compiling to non-default memory modes
  -QOL improvement by adding a note on how to make path variables permenant when configuring Arm compilers

Change-Id: Id798b25638260721d8e48468b7a5942bd802d63b