Revert^2 "Add the 'bdev_type' attribute to all block devices" am: 03b647d205 am: c050e67988

Original change: https://android-review.googlesource.com/c/device/linaro/dragonboard/+/1862222

Change-Id: I56bedf498602b9a9f8ca0c3d66e6a02043911f7f