LU-8066 mdd: migrate from proc to sysfs

LU-8066 mdd: migrate from proc to sysfs

Move the ofd module from using proc for most single value files
to sysfs. The more complex proc entries are moved to debugfs.

Change-Id: I01eebf1c58f1a13c2f5e8c599a1363c80468b0bd
Signed-off-by: James Simmons <uja.ornl@yahoo.com>
Reviewed-on: https://review.whamcloud.com/33632
Tested-by: Jenkins
Tested-by: Maloo <maloo@whamcloud.com>
Reviewed-by: Alex Zhuravlev <bzzz@whamcloud.com>
Reviewed-by: Andreas Dilger <adilger@whamcloud.com>
Reviewed-by: Oleg Drokin <green@whamcloud.com>