The recent change enabling parallel make for ptest compile/install caused
autobuilder failures in these two recipes. Disable parallel make here
for now until someone can debug the race and get it fixed (preferably
upstream).
(From OE-Core rev: 12755e3e771eb2f1628e2b3dd7138c8766973d82)
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>