Revert^2 "Add the 'bdev_type' attribute to all block devices" am: 03b647d205 am: c050e67988 am: 4a49da307b

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

Change-Id: I577c58d17fa6555e49de60f6aed5a23211b6e60b