Remove legacy BMC code update services

The services in obmc-flash-bmc and obmc-mgr-download are deprecated,
remove them.

Tested: Verify the legacy services are not built; and code update works
        with APIs described in
        https://github.com/openbmc/phosphor-dbus-interfaces/tree/master/xyz/openbmc_project/Software

Change-Id: I192940528914ad263b1142a9955d3df201f3cb8c
Signed-off-by: Lei YU <mine260309@gmail.com>
diff --git a/recipes-phosphor/packagegroups/packagegroup-obmc-apps.bb b/recipes-phosphor/packagegroups/packagegroup-obmc-apps.bb
index e25a1f2..c783d00 100644
--- a/recipes-phosphor/packagegroups/packagegroup-obmc-apps.bb
+++ b/recipes-phosphor/packagegroups/packagegroup-obmc-apps.bb
@@ -101,11 +101,7 @@
         ${VIRTUAL-RUNTIME_obmc-sensors-hwmon} \
         "
 
-# These packages are not required with UBI enabled
-${PN}-software-extras = " \
-        obmc-flash-bmc \
-        obmc-mgr-download \
-        "
+${PN}-software-extras = ""
 
 ${PN}-software-extras_df-obmc-ubi-fs = " \
         phosphor-image-signing \