db845c: Unify fstab files to fix issues w/ adb remount am: e53665ed85 am: 222ed0b556

Original change: https://android-review.googlesource.com/c/device/linaro/dragonboard/+/1449169

Change-Id: Ic6e43e89448d81cb1141a49b2a02f6b52e0e0a2d