Add an optional empty property - 'inactive' for reserved memory, only do effect for regions with reusable property. CMA area in 'inactive' status means that the operating system can't alloc pages from the regions. Change-Id: I34ecde9bc9c2e3cec175e6c032911c1bae21295c Signed-off-by: Jianqun Xu <jay.xu@rock-chips.com>