LU-5443 lustre: replace direct HZ access with kernel APIs

LU-5443 lustre: replace direct HZ access with kernel APIs

On some customer's systems, kernel was compiled with HZ defined to
100, instead of 1000. This improves performance for HPC applications.
However, to use these systems with Lustre, customers have to re-build
Lustre for the kernel because Lustre directly uses the defined
constant HZ.

Since kernel 2.6.21, some non-HZ dependent timing APIs become non-
inline functions, which can be used in Lustre codes to replace the
direct HZ access.

These kernel APIs include:
 jiffies_to_msecs()
 jiffies_to_usecs()
 jiffies_to_timespec()
 msecs_to_jiffies()
 usecs_to_jiffies()
 timespec_to_jiffies()

And here are some samples of the replacement:
 HZ            -> msecs_to_jiffies(MSEC_PER_SEC)
 n * HZ        -> msecs_to_jiffies(n * MSEC_PER_SEC)
 HZ / n        -> msecs_to_jiffies(MSEC_PER_SEC / n)
 n / HZ        -> jiffies_to_msecs(n) / MSEC_PER_SEC
 n / HZ * 1000 -> jiffies_to_msecs(n)

This patch replaces the direct HZ access in lustre modules.

Signed-off-by: Jian Yu <jian.yu@intel.com>
Change-Id: Ib0ed9b5faf6ed311ff5423873d1c125b02ec4ab5
Reviewed-on: http://review.whamcloud.com/12052
Reviewed-by: Bob Glossman <bob.glossman@intel.com>
Reviewed-by: Dmitry Eremin <dmitry.eremin@intel.com>
Tested-by: Jenkins
Reviewed-by: James Simmons <uja.ornl@gmail.com>
Reviewed-by: Nathaniel Clark <nathaniel.l.clark@intel.com>
Tested-by: Maloo <hpdd-maloo@intel.com>
Reviewed-by: Oleg Drokin <oleg.drokin@intel.com>