LU-8066 obd: migrate to ksets

Lustre's sysfs only uses kobjects but with the introduction of
ksets we can use functionality like kset_find_kobj() and uevents.
Currently lustre is layered as lustre_kobj -> class -> obd device.
This patch changes the obd devices and the top level lustre_kobj
into ksets. The class level is kept as kobjects but are bound to
the top level lustre kset so they searchable and uevents can be
created for them. Also much of the class functionality can be
replaced with what ksets can do. With obd devices now ksets we
can replace lprocfs_kset_register with lprocfs_obd_setup. Some
of the sysfs attributes were not cleaned up so added proper
removal. Reversed what the default sysfs attributes are. This
will be needed for the replacement functionality for
class_process_proc_param().

Change-Id: I3ced5f69ace6a0a9a6bc51957f20a0caecdbafc9
Signed-off-by: James Simmons <uja.ornl@yahoo.com>
Reviewed-on: https://review.whamcloud.com/28948
Reviewed-by: John L. Hammond <john.hammond@intel.com>
Tested-by: Jenkins
Tested-by: Maloo <hpdd-maloo@intel.com>
Reviewed-by: Sonia Sharma <sonia.sharma@intel.com>
Reviewed-by: Oleg Drokin <oleg.drokin@intel.com>