ppc64le entry is needed in config.guess file about snappy HOT 4 OPEN

PowerPC now has the Little Endian version of it. So to make snappy buildable in 
we need ppc64le entry in config.guess file like below,

ppc64le:Linux:*:*)
    echo powerpc64le-unknown-linux-gnu
    exit ;;

FWIW, config.sub comes from autotools, so if you just rerun autogen.sh, you 
will get a new version. (We do not maintain this file by hand.) But I agree 
that we will want to do that in the released tarballs at some point, too.

It is better to have the entry in the releaed snappy-1.1.1 and snappy-1.1.2 
tarballs since we are using JNI wrapper( xerial github) to build snappyjava in 
PowerPC Little Endian and it fails due to this missing entry.

We are of course not going to go back and modify Snappy 1.1.1 or 1.1.2 after 
the fact. Any such fix would be in an 1.1.3 release or similar.