meta-facebook: emmc: add blkdiscard and mmc utils

In order to erase emmc devices, it is useful to have the blkdiscard and
mmc utilities installed.  Add the appropriate packages to any machine
with the secondary-emmc device.

Signed-off-by: Patrick Williams <patrick@stwcx.xyz>
Change-Id: I376fca98267770f104866fa064d3018b8ba7e3b1
diff --git a/meta-facebook/recipes-phosphor/images/fb-phosphor-image.inc b/meta-facebook/recipes-phosphor/images/fb-phosphor-image.inc
index 7b1ab65..1c2281e 100644
--- a/meta-facebook/recipes-phosphor/images/fb-phosphor-image.inc
+++ b/meta-facebook/recipes-phosphor/images/fb-phosphor-image.inc
@@ -20,7 +20,11 @@
     tmux \
     wget \
     "
-OBMC_IMAGE_EXTRA_INSTALL:append:mf-fb-secondary-emmc = " emmc-init"
+OBMC_IMAGE_EXTRA_INSTALL:append:mf-fb-secondary-emmc = " \
+    emmc-init \
+    mmc-utils \
+    util-linux-blkdiscard \
+    "
 
 IMAGE_LINGUAS="en-us"