openpower-build-setup: Use correct target

Signed-off-by: Joel Stanley <joel@jms.id.au>
diff --git a/openpower-build-setup.sh b/openpower-build-setup.sh
index 80a8a83..93cd408 100755
--- a/openpower-build-setup.sh
+++ b/openpower-build-setup.sh
@@ -76,10 +76,10 @@
 . op-build-env
 
 # Configure
-make ${target}_defconfig
+op-build ${target}_defconfig
 
 # Kick off a build
-make
+op-build
 
 EOF_SCRIPT