linaro_swr: Make it a 64bit only build target am: ab68f0ee84 am: e6fe95e2cb am: ff347e1bce

Original change: https://android-review.googlesource.com/c/device/linaro/dragonboard/+/2785579

Change-Id: I7828f180732dbbeb600659bfb82f82786455eae3
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>