mm: Allow pages that are swapped in to come from the movable zone

Pages that are swapped out are pages that can reside in the movable
zone. However, when they are swapped in, they are restricted to the
normal zone, when they can reside in the movable zone again. Set the
GFP flags accordingly for swapin allocations, so that they can be
satisfied from the movable zone.

Change-Id: I25919034a5197a1c4f830e498d32347aa460187f
Signed-off-by: Isaac J. Manjarres <isaacm@codeaurora.org>