Unimplemented pause should not change vm state on PowerVM

The instance of PowerVM does not support pause, but
after pause the instance, the state change to PAUSED,
it's unreasonable.

Change-Id: I4fb184388c37ea8708cdacc173dc1b2dbd4d1597
Fixes: bug #1202082
Merge "Unimplemented pause should not change vm state on PowerVM"