Add functional property for each tach sensor

Each fan's tach sensor creates a child inventory object under the fan's
inventory path containing the sensor's functional state. This child
inventory object path is the fan's path plus the tach sensor's defined
id.
i.e.)
/xyz/openbmc_project/inventory/system/chassis/motherboard/fan0/fan0_0

Change-Id: I0fe5000eadbe55d60b475ccad700b0264ed0ac75
Signed-off-by: Matthew Barth <msbarth@us.ibm.com>
4 files changed