Add rngd to image

Resolves openbmc/openbmc#1367

Change-Id: I3f5a48a8fa84b1c02f8c560cb678175f5f329cf6
Signed-off-by: Leonel Gonzalez <lgonzalez@us.ibm.com>
diff --git a/classes/obmc-phosphor-image.bbclass b/classes/obmc-phosphor-image.bbclass
index 3766c73..e37acc7 100644
--- a/classes/obmc-phosphor-image.bbclass
+++ b/classes/obmc-phosphor-image.bbclass
@@ -86,6 +86,7 @@
         ${OBMC_IMAGE_EXTRA_INSTALL} \
         ffdc \
         rsync \
+        rng-tools \
         "
 
 OBMC_IMAGE_EXTRA_INSTALL ?= ""