lib/stm32wb/hci: app_conf.h: Re-apply patch Z-WB-3

When updating stm32wb hci lib from V1.12.0 to V1.13.0,
Zephyr specific patch Z-WB-3 (which configures BLE controller
firmware to work in mode LL only) was overwitten.
As a consequence, it was not possible to establish BLE connection
anymore.
Set it back.

(cherry picked from commit 300109f80730cb2477bfcc706a6602b9870336b3)

Signed-off-by: Erwan Gouriou <erwan.gouriou@linaro.org>
GitOrigin-RevId: 300109f80730cb2477bfcc706a6602b9870336b3
Change-Id: I33e6119c5e0b15ad78118aead28132fa9f79aec3
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/third_party/zephyr/hal_stm32/+/3430254
Tested-by: CopyBot Service Account <copybot.service@gmail.com>
Reviewed-by: Jack Rosenthal <jrosenth@chromium.org>
Commit-Queue: Jack Rosenthal <jrosenth@chromium.org>