MLECO-1935: All common CMake user options consolidated.

For easier look up and maintenance, all common CMake user options
have been consolidated in one CMake file.

NOTE: the individual use case specific options are still within
      the correspoinding use case CMake files.

Change-Id: Id887f7b2c763f4d3eb997d997cf466684d0089b6
diff --git a/scripts/cmake/native-sources.cmake b/scripts/cmake/native-sources.cmake
index 2a5b0ae..6ebf435 100644
--- a/scripts/cmake/native-sources.cmake
+++ b/scripts/cmake/native-sources.cmake
@@ -20,7 +20,7 @@
 
 if (ETHOS_U_NPU_ENABLED)
     message(WARNING "EthosU can't be enabled for native builds."
-                    "Use -DETHOS_U_NPU_ENABLED=0 flag for this target platform."
+                    "Use -DETHOS_U_NPU_ENABLED=OFF flag for this target platform."
                     "Overriding, disabling use of EthosU...")
     set(ETHOS_U_NPU_ENABLED OFF)
 endif()