LU-9859 libcfs: merge UMP and SMP libcfs cpu header code

LU-9859 libcfs: merge UMP and SMP libcfs cpu header code

Currently we have two headers, linux-cpu.h that contains the SMP
version and libcfs_cpu.h contains the UMP version. We can simplify
the headers into a single header which handles both cases. Many
cleanups for checkpatch violations are done as well.

Change-Id: Ifb92e59ad370e991220b5957538b6bab89423e2f
Signed-off-by: James Simmons <uja.ornl@yahoo.com>
Reviewed-on: https://review.whamcloud.com/30873
Tested-by: Jenkins
Tested-by: Maloo <hpdd-maloo@intel.com>
Reviewed-by: Andreas Dilger <andreas.dilger@intel.com>
Reviewed-by: Dmitry Eremin <dmitry.eremin@intel.com>
Reviewed-by: Oleg Drokin <oleg.drokin@intel.com>