Add machine types people use as host for TF builds.

PiperOrigin-RevId: 308980315
Change-Id: I56d4a8045b41265a26c9a75e6431531e774d04db
diff --git a/third_party/remote_config/remote_platform_configure.bzl b/third_party/remote_config/remote_platform_configure.bzl
index 3935aa7..185120f 100644
--- a/third_party/remote_config/remote_platform_configure.bzl
+++ b/third_party/remote_config/remote_platform_configure.bzl
@@ -14,8 +14,11 @@
     cpu = "x86_64"
     if "MACHTYPE" in repository_ctx.os.environ:
         machine_type = repository_ctx.os.environ["MACHTYPE"]
-        if machine_type.startswith("ppc"):
+        if (machine_type.startswith("ppc") or
+            machine_type.startswith("powerpc")):
             cpu = "ppc"
+        elif machine_type.startswith("s390x"):
+            cpu = "s390x"
 
     exec_properties = repository_ctx.attr.platform_exec_properties