staging: lustre: split kernel comm between user and kernel

Split the kernel comm header in libcfs into two new headers
to handle both kernel space and user space for the lustre layer.
This is broken out of the original patch 14270. The part covered
by this change is as follows:

The original libcfs_kernelcomm.h header is split into three parts:
  * lustre_kernelcomm.h, a new header for the kernel parts;
  * uapi_kernelcomm.h, a new header for the data structures shared
    between userspace and kernelspace;
  * lustreapi_internal.h receives the private liblustreapi prototypes.

Various names and filenames have been harmonized to *kernelcomm*.

The unused symbol KUC_FL_BLOCK has been removed.

Signed-off-by: frank zago <fzago@cray.com>
Intel-bug-id: https://jira.hpdd.intel.com/browse/LU-6245
Reviewed-on: http://review.whamcloud.com/14270


Reviewed-by: Nathan Rutman <nathan.rutman@seagate.com>
Reviewed-by: James Simmons <uja.ornl@yahoo.com>
Reviewed-by: Dmitry Eremin <dmitry.eremin@intel.com>
Reviewed-by: John L. Hammond <john.hammond@intel.com>
Reviewed-by: Oleg Drokin <oleg.drokin@intel.com>
Signed-off-by: James Simmons <jsimmons@infradead.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>