Revert "Add the 'bdev_type' attribute to all block devices" am: a349fb7f96 am: 92618c701b am: e1aa506b42

Original change: https://android-review.googlesource.com/c/device/linaro/poplar/+/1850578

Change-Id: I49a59cce79399fad39f8375f9ad7635efc38836c