BugLink: http://bugs.launchpad.net/bugs/1546572

Rather than hardcode it.

v2: integrate spc fix from Rex
Reviewed-by: Jammy Zhou <Jammy.Zhou@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
(cherry picked from commit 834b694c)
Signed-off-by: Alberto Milone <alberto.milone@canonical.com>
Signed-off-by: Tim Gardner <tim.gardner@canonical.com>