Update the OPAL glue configure code to correctly link the opal/pmix3
component to the hwloc used by OMPI instead of defaulting to the
system-level hwloc. Required a corresponding update to the PMIx hwloc
configure code so we treat hwloc the same way we handle libevent in
embedded scenarios. Roll to PMIx v3.1.2 for plugging of memory leaks and
addition of faster PMIx_Get response
Signed-off-by: Ralph Castain <rhc@pmix.org>
335f8c5100