config: Move AFS_LRALLOCSIZ to afs_args.h

AFS_LRALLOCSIZ is currently defined in afs/afs.h.  Other memory
related definitions such as AFS_SMALLOCSIZ and AFS_MDALLOCSIZ
are defined in config/afs_args.h.  Move AFS_LRALLOCSIZ to
config/afs_args.h for consistency.

Reviewed-on: http://gerrit.openafs.org/11174
Tested-by: BuildBot <buildbot@rampaginggeek.com>
Reviewed-by: Chas Williams - CONTRACTOR <chas@cmf.nrl.navy.mil>
Reviewed-by: D Brashear <shadow@your-file-system.com>
(cherry picked from commit 02565591855f5a5ddb7dd6e308d9f535c2fd64b8)

Change-Id: I691a7d6025a1b4353f479049d09c54297b80989c
Reviewed-on: http://gerrit.openafs.org/11209
Tested-by: BuildBot <buildbot@rampaginggeek.com>
Reviewed-by: Perry Ruiter <pruiter@sinenomine.net>
Reviewed-by: Andrew Deason <adeason@sinenomine.net>
Reviewed-by: Benjamin Kaduk <kaduk@mit.edu>
Reviewed-by: Stephan Wiesand <stephan.wiesand@desy.de>