Add storage utilization functions

1. Add "path" in HealthConfig for storage and inode functions.
2. Add storage and inode functions to calculate each utilization by
   "path" (filesystem path).

Tested: verified the storage object path will auto generate when
bmc_health_config.json setting correct and collect the storage utilization.

Signed-off-by: Bruce Lee <Bruce_Lee@quantatw.com>
Change-Id: I4a8fb51b5e85190f908a40d9bf0545ec8167923a
3 files changed