assimp: add .hash file
Fixes:
http://autobuild.buildroot.org/results/f64/f6452c4b0a237219b6ae28c8bb3cf665ad40139f/
http://autobuild.buildroot.org/results/e9a/e9aed367394c6a4ac7b834139b5601e844ba4648/
Similar to jquery-keyboard, it seems the assimp tarball on the autobuilder
is corrupt. Fix it by adding a .hash file so it falls back to our s.b.o
mirror.
Signed-off-by: Peter Korsgaard <peter@korsgaard.com>
Peter Korsgaard