buildroot

wayland: fix build on Blackfin

This commit adds a patch to Wayland that allows the Blackfin
architecture to build this package properly. The problem is due to the
usual __USER_LABEL_PREFIX__ issue on Blackfin.

Fixes:

  http://autobuild.buildroot.org/results/e418b97766c943bf41fc80815c3e625e6a68b12d/

Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>