tile: get rid of superfluous __GFP_REPEAT

__GFP_REPEAT has a rather weak semantic but since it has been introduced
around 2.6.12 it has been ignored for low order allocations.

pgtable_alloc_one uses __GFP_REPEAT flag for L2_USER_PGTABLE_ORDER but
the order is either 0 or 3 if L2_KERNEL_PGTABLE_SHIFT for HPAGE_SHIFT.
This means that this flag has never been actually useful here because it
has always been used only for PAGE_ALLOC_COSTLY requests.

Link: http://lkml.kernel.org/r/1464599699-30131-16-git-send-email-mhocko@kernel.org
Signed-off-by: Michal Hocko <mhocko@suse.com>
Acked-by: Chris Metcalf <cmetcalf@mellanox.com> [for tile]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>