chromeos: config: armel: enable full L2 maintenance

chromeos: config: armel: enable full L2 maintenance

When allocation is bigger than L2 size it is more optimal to
flush or writeback whole L2 instead of doing maintenance
for each allocated page.

bug 983964

Change-Id: Ibb3609be71621ff9ab75bea9146bfe7578f9315a
Signed-off-by: Kirill Artamonov <kartamonov@nvidia.com>
Reviewed-on: http://git-master/r/127835
Reviewed-by: Rhyland Klein <rklein@nvidia.com>
Reviewed-by: Juha Tukkinen <jtukkinen@nvidia.com>
Rebase-Id: R4f11c9629479bc33ab45b31ce3212367b6c5f7e7