arm: exynos: Modify heap creation code

This makes heap creation safe to call form machine reserve

Change-Id: I3b307a4865f28f13da7cf39e6935a1fe38f041ea
Signed-off-by: Rebecca Schultz Zavin <rebecca@android.com>
Signed-off-by: franciscofranco <franciscofranco.1990@gmail.com>