Revert "Revert^2 "Add the 'bdev_type' attribute to all block devices"" am: f6af322852 am: db5b3355b3

Original change: https://android-review.googlesource.com/c/device/linaro/poplar/+/1862419

Change-Id: I69f2b92d8cc5f428f123da122f63aa6bf9fc4d1e