control: Display locked targets in debug dump

The override_fan_target action can lock individual fan targets to a
value that is different than the zone target that the rest of the fans
are set to.

This change adds those locked target values to the 'zones' section of
the debug dump:

    "target_locks": {
        "fan0": [
            11300
        ],
        "fan3": [
            11300
        ]
    }

And when there are no locks:

    "target_locks": {}

Signed-off-by: Matt Spinler <spinler@us.ibm.com>
Change-Id: I2c4cfa317028db8843d361e79b270d612aacdd87
2 files changed