Add mmrenderer configure check

No all QNX versions/variations have a mmrenderer by
default, so we need to check for it, otherwise
it fails to compile.

Change-Id: I3efe9df37cf7807c1b0ac4d2e8f49aa02e3408cd
Reviewed-by: Frank Osterfeld <frank.osterfeld@kdab.com>
Reviewed-by: Rafael Roquetto <rafael.roquetto@kdab.com>
Reviewed-by: Lars Knoll <lars.knoll@digia.com>