openpower/scripts: Check (with travis) that defconfigs are correct

Signed-off-by: Stewart Smith <stewart@linux.ibm.com>
diff --git a/openpower/scripts/update-defconfigs.sh b/openpower/scripts/update-defconfigs.sh
new file mode 100644
index 0000000..c82900c
--- /dev/null
+++ b/openpower/scripts/update-defconfigs.sh
@@ -0,0 +1,18 @@
+#!/bin/bash -x
+
+set -uo pipefail
+
+. op-build-env
+
+for c in openpower/configs/*defconfig; do
+	PLATFORM=`basename $c _defconfig`
+	PLATFORM_DEFCONFIG=`basename $c`
+	echo $PLATFORM
+	ODIR=`mktemp -d`
+	op-build O=$ODIR $PLATFORM_DEFCONFIG
+	op-build O=$ODIR olddefconfig
+	op-build O=$ODIR savedefconfig
+	rm -rf $ODIR
+done
+
+git diff --exit-code