LU-8066 llite: move /proc/fs/lustre/llite/kbytes* to sysfs

LU-8066 llite: move /proc/fs/lustre/llite/kbytes* to sysfs

Move kbytestotal, kbytesavail and kbytesfree files from
/proc/fs/lustre/llite/* to /sys/fs/lustre/llite/*/

This is a modified version of

Linux-commit: 5804b11e1487558c6740282a01a08bb4ba0c6d06

due to the large amount of changes to the OpenSFS/Intel branch.

Change-Id: Ifb43c01bb0055051cecb01ed6a183d1797d3870e
Signed-off-by: Oleg Drokin <green@linuxhacker.ru>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: James Simmons <uja.ornl@yahoo.com>
Reviewed-on: https://review.whamcloud.com/32497
Reviewed-by: Andreas Dilger <adilger@whamcloud.com>
Reviewed-by: Bobi Jam <bobijam@hotmail.com>
Tested-by: Jenkins
Tested-by: Maloo <hpdd-maloo@intel.com>
Reviewed-by: Oleg Drokin <green@whamcloud.com>