scripts: use local directory if workspace not defined.

Determine workspace if environment variable not defined.

Signed-off-by: Liam Girdwood <liam.r.girdwood@linux.intel.com>

Author: lrgirdwo

scripts/sof-testbench-helper.sh

@@ -32,8 +32,11 @@ usage() {
 }
 
 if [ -z "${SOF_WORKSPACE}" ]; then
-    echo "Error: environment variable SOF_WORKSPACE need to be set to top level sof directory"
-    exit 1
+    # fallback to the script directory default path
+    SCRIPT_DIR=$(cd "$(dirname "$0")" && pwd)
+    SOF_REPO=$(dirname "$SCRIPT_DIR")
+    SOF_WORKSPACE="$SOF_REPO/../"
+    echo "Using default SOF environment at $SOF_WORKSPACE"
 fi
 
 OUTWAV=