packagegroups: Remove obmc-mgr-system

The system manager (obmc-mgr-system) which provided GPIO
functionality is being deprecated and it's not in use anymore:
* GPIOs have moved out of D-Bus (see openbmc/openbmc#3332).
* Tools depending on its GPIO functions have been updated to
call local functions instead.
* The systemd service files have been updated to not depend
on system manager.

Tested: Powered on a Witherspoon with no errors.

Change-Id: I98a00cfc274eca0e8ef53bfa3aac57e8c64dd72f
Signed-off-by: Adriana Kobylak <anoo@us.ibm.com>
diff --git a/recipes-phosphor/packagegroups/packagegroup-op-apps.bb b/recipes-phosphor/packagegroups/packagegroup-op-apps.bb
index bb05336..421789d 100644
--- a/recipes-phosphor/packagegroups/packagegroup-op-apps.bb
+++ b/recipes-phosphor/packagegroups/packagegroup-op-apps.bb
@@ -53,7 +53,6 @@
 
 SUMMARY_${PN}-system = "OpenPOWER System"
 RDEPENDS_${PN}-system = " \
-        obmc-mgr-system \
         hostboot-settings \
         pdbg \
         "