gitian-linux: Extend noexec-stack workaround to powerpc

contrib/gitian-descriptors/gitian-linux.yml

@@ -130,7 +130,7 @@ script: |
   # Extract the git archive into a dir for each host and build
   for i in ${HOSTS}; do
     export PATH=${BASEPREFIX}/${i}/native/bin:${ORIGPATH}
-    if [ "${i}" = "riscv64-linux-gnu" ]; then
+    if [ "${i}" = "riscv64-linux-gnu" ] || [ "${i}" = "powerpc64-linux-gnu" ] || [ "${i}" = "powerpc64le-linux-gnu" ]; then
       # Workaround for https://bugs.launchpad.net/ubuntu/+source/gcc-8-cross-ports/+bug/1853740
       # TODO: remove this when no longer needed
       HOST_LDFLAGS="${HOST_LDFLAGS_BASE} -Wl,-z,noexecstack"