LU-10906 llite: create checksums to replace checksum_pages

LU-10906 llite: create checksums to replace checksum_pages

Create llite.*.checksums, which matches llite.*.checksum_pages in
functionality. Now the llite layer have something that matches
osc.*.checksums. In time we can retire checksum_pages and change
it to its original purpose of enabling per-page checksums (which
was not implemented in the CLIO development).

Test-Parameters: trivial

Change-Id: I0e381e3626e835a448a6285cb81d27d67af93a54
Signed-off-by: James Simmons <uja.ornl@yahoo.com>
Reviewed-on: https://review.whamcloud.com/33222
Tested-by: Jenkins
Tested-by: Maloo <hpdd-maloo@intel.com>
Reviewed-by: Andreas Dilger <adilger@whamcloud.com>
Reviewed-by: Li Xi <lixi@ddn.com>
Reviewed-by: Emoly Liu <emoly@whamcloud.com>
Reviewed-by: Oleg Drokin <green@whamcloud.com>