staging: ion: Add GFP_NO_KSWAPD flag to high order allocations

When allocating from system heap we try higher order allocations first
before falling back on lower allocations. However, we do not want to
incur much overhead by doing the fallback. So don't try to run kswapd
during these allocation attempts.

CRs-fixed: 660049
Change-Id: I80895c456c80342cc3b2100470dfd9550c81bd29
Signed-off-by: Olav Haugan <ohaugan@codeaurora.org>