Add witherspoon defconfig, p9 support for hostboot

Opened RTC issues 160270 and 160273 to fix patches that were
added.
diff --git a/openpower/package/occ/Config.in b/openpower/package/occ/Config.in
index f00396d..29b5eb4 100644
--- a/openpower/package/occ/Config.in
+++ b/openpower/package/occ/Config.in
@@ -1,6 +1,6 @@
 config BR2_PACKAGE_OCC
         bool "occ"
-        default y if (BR2_OPENPOWER_PLATFORM && BR2_powerpc_power8)
+        default y if (BR2_OPENPOWER_PLATFORM)
         select BR2_CPP
         help
             Project to build OCC