This sits behind the mailbox interface, and implements
request/response queries for system properties. The
framebuffer-related properties will be added in a later patch.
Reviewed-by: Peter Crosthwaite <crosthwaite.peter@gmail.com>
Signed-off-by: Andrew Baumann <Andrew.Baumann@microsoft.com>
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
