LU-56 ksocklnd: CPT affinity socklnd

this patch covered a few things:
- implement percpt scheduler threads for socklnd
- decrease overall threads number for fat core machine
- create more threads only if there are more than one NIC
- remove IRQ affinity implementation from socklnd
  IRQ affinity is not very helpful because CPUs on modern computer
  are very powerful. Also, user can still setup IRQ affinity via
  /proc and cpu_pattern of libcfs

Signed-off-by: Liang Zhen <liang@whamcloud.com>
Change-Id: Idfa19037a529fe96cb1432cbd7f55a5dfac89d29
Reviewed-on: http://review.whamcloud.com/2718
Reviewed-by: Lai Siyao <laisiyao@whamcloud.com>
Reviewed-by: Doug Oucharek <doug@whamcloud.com>
Tested-by: Hudson
Tested-by: Maloo <whamcloud.maloo@gmail.com>
Reviewed-by: Oleg Drokin <green@whamcloud.com>