Add mig config watch then reload config file

[lengrongfu]

NVIDIA/gpu-operator#891

About this issue, I want to add some logic to watch for changes in the /mig-parted-config/config.yaml file and trigger a reload of the configuration file.

[lengrongfu]

eg:
custom-config before config value is:

version: v1
mig-configs:
 custom-config:
    - devices: all
       mig-enabled: true
       mig-devices:
         3g.40gb: 2

custom-config after config value is:

version: v1
mig-configs:
 custom-config:
    - devices: all
       mig-enabled: true
       mig-devices:
         1g.10gb: 3
         2g.20gb: 2

When only config is modified, mig-pared apply will not be triggered.