msm: kgsl: stop using gen_pool_alloc_aligned

All allocations made from the pool use the same alignment,
so it is simpler to just increase the overall pool order
to get the needed alignment.

Change-Id: I6de5069388bf8344d60902dedea795f7c5629f54
Signed-off-by: Jeremy Gebben <jgebben@codeaurora.org>