Arm backend: Remove setup flag for model test deps

Remove the setup.sh --setup-test-dependency option and document calling
the model test dependency installer directly instead.

Change-Id: Ie95366b20ae88bf1a39d1f0ccb9d573a0fb6bda9
Signed-off-by: Sebastian Larsson <sebastian.larsson@arm.com>

Author: Sebastian-Larsson

backends/arm/README.md

@@ -249,10 +249,15 @@ Some tests, with `u55`, `u85` and `vgf` in the name require external dependencie
   ```
 
 In addition, some model tests in the Arm backend require third-party libraries or packages.
-To run these tests, you need to install the required dependencies by running the script `examples/arm/setup.sh` with the flag `--setup-test-dependency`.
+To run these tests, install the required dependencies directly:
 
-Please note that installing model test dependencies is a standalone process. When using the `--setup-test-dependency` flag,
-the script will install only the necessary dependencies for model tests, skipping all other setup procedures.
+```
+bash backends/arm/scripts/install_models_for_test.sh
+```
+
+Installing model test dependencies is a standalone process. The script installs
+only the dependencies needed for model tests, skipping all other setup
+procedures.
 
 ## Using git hooks
 

examples/arm/setup.sh

@@ -182,11 +182,6 @@ function check_options() {
                 enable_vulkan_sdk=1
                 shift
                 ;;
-            --setup-test-dependency)
-                log_step "deps" "Installing test dependency..."
-                source $et_dir/backends/arm/scripts/install_models_for_test.sh
-                exit 0
-                ;;
             --help)
                 print_usage "$@"
                 exit 0