LU-17422 obdclass: move page pools to obdclass

LU-17422 obdclass: move page pools to obdclass

This patch starts the process of moving page pools to
obdclass by moving the file and making the changes necessary
to compile and run Lustre with the file moved.

This does not rename anything in the file yet, that will be
done in subsequent patches.

Signed-off-by: Patrick Farrell <patrick.farrell@oracle.com>
Change-Id: Iff39dd9ddfb105773f8eafa4754d32189067189b
Reviewed-on: https://review.whamcloud.com/c/fs/lustre-release/+/53667
Tested-by: jenkins <devops@whamcloud.com>
Tested-by: Maloo <maloo@whamcloud.com>
Reviewed-by: Sebastien Buisson <sbuisson@ddn.com>
Reviewed-by: Andreas Dilger <adilger@whamcloud.com>
Reviewed-by: Oleg Drokin <green@whamcloud.com>