attr: Disable parallel make install
do_install fails on newer versions of make with interesting and hard to
debug errors. Disablle parallle make install as a workaround. Later verisons
of attr in newer releases don't have the issue.
(From OE-Core rev: 6043b9a2ea879f8960897b11eb947801508a94da)
(From OE-Core rev: f06861bbe402fff3f370687585e43c0270609d00)
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>