Make sure we keep building grep now it's broken out from toolbox.

Change-Id: Ib71e37c5ba238136a9790cd92ecec745e099341e
diff --git a/target/product/embedded.mk b/target/product/embedded.mk
index aae7f95..56a5f97 100644
--- a/target/product/embedded.mk
+++ b/target/product/embedded.mk
@@ -26,6 +26,7 @@
     dumpstate \
     dumpsys \
     gralloc.default \
+    grep \
     gzip \
     healthd \
     init \