haven: Add Haven Message Queue driver

Add Haven message queue driver provides an interface to the client
drivers running on the virtual machines to communicate with the clients
running on other virtual machines. The services offered by the driver is
simply to send and receive messages.

Change-Id: I1685109f579eaf7fa039225dd60a42adae7de00a
Signed-off-by: Raghavendra Rao Ananta <rananta@codeaurora.org>
Signed-off-by: Elliot Berman <eberman@codeaurora.org>