Introducing the refactors of the block device to allow a tree-like
configuration, and start using it for the partitions level.
Based on patch I3600c6a3d663c697b59d91bd3fbb5e408af345e4
Change-Id: I58bb3c256a1dfd100d29266571c333c2d43334f7
Co-Authored-By: Andreas Florath <andreas@florath.net>