gpu: ion: Modify gfp flags in ion_system_heap

When allocations larger than order 4 are made, use _GFP_NORETRY
and __GFP_NO_KSWAPD so kswapd doesn't get kicked off to reclaim
these larger chunks.  For smaller allocaitons, these are
unnecessary, as the system should be able to reclaim these.

Change-Id: Iae569b97a7a4db03bbd702bbbb99c160be7710c3
Signed-off-by: Rebecca Schultz Zavin <rebecca@android.com>
Git-commit: fddfe77af30cfbf5396dbdfa9d3f4fca260daa72
Git-repo: https://android.googlesource.com/kernel/common


Signed-off-by: Laura Abbott <lauraa@codeaurora.org>