l3afpad: add check for GTK3DISTROFEATURES
We want world builds without GTK3DISTROFEATURES to work.
(From OE-Core rev: 0b2945588f7b539836369895dc7d3d2629abb431)
Signed-off-by: Joe Slater <jslater@windriver.com>
Signed-off-by: Ross Burton <ross.burton@intel.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>