PM / Hibernate: Remove the old memory-bitmap implementation

The radix tree implementatio is proved to work the same as
the old implementation now. So the old implementation can be
removed to finish the switch to the radix tree for the
memory bitmaps.
Signed-off-by: Joerg Roedel <jroedel@suse.de>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>