hwloc201: use a git submodule

Remove the entire opal/mca/hwloc/hwloc201/hwloc directory, which was
just an expended hwloc v2.0.1 tarball.  Replace it with a git
submodule pointing to https://github.com/open-mpi/hwloc.git at the
hash 4fe5f41804eaf2bcd84e7ac98dc82f6e3df04b86, which is equivalent to
the hwloc-2.0.1 tag.

Signed-off-by: Jeff Squyres <[email protected]>

Author: jsquyres

.gitmodules

@@ -0,0 +1,3 @@
+[submodule "opal/mca/hwloc/hwloc201/hwloc"]
+	path = opal/mca/hwloc/hwloc201/hwloc
+	url = https://github.com/open-mpi/hwloc.git

opal/mca/hwloc/hwloc201/autogen.subdirs

@@ -0,0 +1 @@
+hwloc