haven: Add support for the MEM_RELEASE/MEM_RECLAIM calls

The MEM_RELEASE/MEM_RECLAIM RM calls are required to unmap memory
from the RM managed page-tables of VMs, as well as for VMs that
own memory to reclaim it respectively, so add support for it.

Change-Id: I6b8025cb08067331deb9cc89ec1d36c94c959c59
Signed-off-by: Isaac J. Manjarres <isaacm@codeaurora.org>