FRU: Invalidate cache when frus change

This creates a match for FruDevice changes and
update the cache when one changes.

Tested:
ipmitool fru list immediately after rescan
had correct values. fru list was faster

Change-Id: I2f332814bd1a0ef38a87dc31b8cd3c16fa6b8d76
Signed-off-by: James Feist <james.feist@linux.intel.com>
1 file changed