staging/lustre/llite: merge lclient.h into llite/vvp_internal.h

Move the definition of struct cl_client_cache to
lustre/include/cl_object.h and move the rest of
lustre/include/lclient.h in to lustre/llite/vvp_internal.h.

Signed-off-by: John L. Hammond <john.hammond@intel.com>
Reviewed-on: http://review.whamcloud.com/12592
Intel-bug-id: https://jira.hpdd.intel.com/browse/LU-5971


Reviewed-by: Jinshan Xiong <jinshan.xiong@intel.com>
Reviewed-by: James Simmons <uja.ornl@gmail.com>
Signed-off-by: Oleg Drokin <green@linuxhacker.ru>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>