hw/bus: Fix inactivity timeout usage
hw/bus: Fix inactivity timeout usage

Inactivity timeout used for power management was not really using
time value.
- if timeout was greater then 0 it was ignored and device was disabled
  at once instead of later.
- if timeout was 0 device should be disabled at once but it was scheduled
  to be run 1 tick later according to os_callout_reset way

Now checking timeout condition is reversed that seems to be intended
behavior.

mlaz/mynewt-core,mlaz/mynewt-core,mlaz/mynewt-core,mlaz/mynewt-core,mlaz/mynewt-core