Revert^2 "Add the 'bdev_type' attribute to all block devices" am: c4af45caa3 am: fe29feffc6

Original change: https://android-review.googlesource.com/c/device/linaro/poplar/+/1862221

Change-Id: I5a3337aec91ac079601e3b66cf53a1bed3b3be14