linenoise: add .hash file
Fixes:
http://autobuild.buildroot.org/results/b02/b02f03e8d0f8e5bb3dcbb3b28819268389ad1dfe/
http://autobuild.buildroot.org/results/7ba/7bae05e74af886867285d40d61eee73a2fd8dbdf/
Similar to jquery-keyboard, it seems the linenoise 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>