LU-6245 libcfs: remove cfs_fs_time handling

LU-6245 libcfs: remove cfs_fs_time handling

Only the mdd layer uses cfs_fs_time handling and since
it is kernel side code we can easily convert it to the
standard linux kernel time keeping api.

Signed-off-by: James Simmons <uja.ornl@yahoo.com>
Change-Id: I212e0098a847e01e2ddc201a78a790097ba8b0f9
Reviewed-on: http://review.whamcloud.com/17376
Reviewed-by: Andreas Dilger <andreas.dilger@intel.com>
Tested-by: Jenkins
Tested-by: Maloo <hpdd-maloo@intel.com>
Reviewed-by: Dmitry Eremin <dmitry.eremin@intel.com>
Reviewed-by: Frank Zago <fzago@cray.com>
Reviewed-by: Oleg Drokin <oleg.drokin@intel.com>