Handle non-linear and unrecognized linearizations

Since we cannot hope to linearize a linearizable value without
understanding the formula (OEM or future spec), treat all unrecognized
linearizations and non-linearizable and rely upon get sensor reading
factors to determine the value.  Add the capability to actually get
the sensor reading factors and then pass the resultant data through
the same decode_formula that would have been use had the factors
been retrieved through the SDR record.

Change-Id: I4c3a6bbbd6c68f7a0d19c2a7a221eb5fb57c99de
Merge "Handle non-linear and unrecognized linearizations"