scripts: serie_update: fetch submodules

STM32Cube HAL & CMSIS Device drivers are now included as git
submodules in the upstream STM32Cube repos. So we need
a new logic to fetch them & integrate the changes.

(cherry picked from commit 3fe2e327ffebae9407037616090b07b608e8c317)

Original-Signed-off-by: Abderrahmane Jarmouni <abderrahmane.jarmouni-ext@st.com>
GitOrigin-RevId: 3fe2e327ffebae9407037616090b07b608e8c317
Change-Id: If81bfd59fac03d6a3cd315032bab57df0bc74eb1
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/third_party/zephyr/hal_stm32/+/5136603
Tested-by: ChromeOS Prod (Robot) <chromeos-ci-prod@chromeos-bot.iam.gserviceaccount.com>
Reviewed-by: Keith Short <keithshort@chromium.org>
Commit-Queue: Keith Short <keithshort@chromium.org>
Tested-by: Keith Short <keithshort@chromium.org>
2 files changed