The .inc already included this, but the x11 version was overriding it. This is
a problem, as the x11 version still needs opengl as well as x11. Append
instead.
(From OE-Core rev: e2006b11d36e3ead725ae6e5613b6b0087f28029)
Signed-off-by: Christopher Larson <chris_larson@mentor.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>