gpu: ion: do not ask for compound pages in system heap

Change-Id: If84b246ec984ee2ae7b0174c714c8ce7726a6ab1
Signed-off-by: Dima Zavin <dima@android.com>
Git-commit: 8b41f4f3a84b18211c10546a14c9cfda8e4ca33e
Git-repo: https://android.googlesource.com/kernel/common


Signed-off-by: Mitchel Humpherys <mitchelh@codeaurora.org>