sm8x50-userdebug: Add a generic build target for Qcom ARMv9 devboards am: bd765d63de

Original change: https://android-review.googlesource.com/c/device/linaro/dragonboard/+/3022523

Change-Id: I07080d0103f7baf94766ce8a25d2508609bffe12
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>