Add chassis power on/off to obmcutil

The recent refactoring of the systemd target names to power on
and off the chassis had a significant impact to openpower partners
because they'd encoded the systemctl command to power on just
the chassis into a lot of instructions and scripts. There's no
guarantee the team won't do this again in the future so a wrapper
around the command for this function makes sense to have.  Now if
the target name changes, it's all abstracted within obmcutil.

Change-Id: Ib7b1907cf4618cf0985f76f2c5f5c5e04d4c162f
Signed-off-by: Andrew Geissler <andrewg@us.ibm.com>
diff --git a/pytools/obmcutil b/pytools/obmcutil
index 5ebe70b..7217344 100644
--- a/pytools/obmcutil
+++ b/pytools/obmcutil
@@ -62,6 +62,20 @@
         'object_name': '/org/openbmc/control/power0',
         'interface_name': 'org.openbmc.control.Power'
     },
+    'chassison': {
+        'bus_name': 'xyz.openbmc_project.State.Chassis',
+        'object_name': '/xyz/openbmc_project/state/chassis0',
+        'interface_name': 'xyz.openbmc_project.State.Chassis',
+        'property': 'RequestedPowerTransition',
+        'value': 'xyz.openbmc_project.State.Chassis.Transition.On'
+    },
+    'chassisoff': {
+        'bus_name': 'xyz.openbmc_project.State.Chassis',
+        'object_name': '/xyz/openbmc_project/state/chassis0',
+        'interface_name': 'xyz.openbmc_project.State.Chassis',
+        'property': 'RequestedPowerTransition',
+        'value': 'xyz.openbmc_project.State.Chassis.Transition.Off'
+    },
     'poweron': {
         'bus_name': 'xyz.openbmc_project.State.Host',
         'object_name': '/xyz/openbmc_project/state/host0',