Minor updates to occtoolp9

Add option to clear min/max sensors: -SCLEAR
Update "-S type=0xTT,loc=0xLL" to use GET_AME_SENSOR like FSP (faster)
To get old -S behavior, use "-S TYPE=0xTT,LOC=0xLL"
Add basic support for cmds via rest: -B
Minor cleanup and additional error checking

Change-Id: If468b8b413b7d5964f2f50e63cb6429d9125257d
Reviewed-on: http://rchgit01.rchland.ibm.com/gerrit1/90682
Tested-by: FSP CI Jenkins <fsp-CI-jenkins+hostboot@us.ibm.com>
Reviewed-by: Martha Broyles <mbroyles@us.ibm.com>
Reviewed-by: Christopher J Cain <cjcain@us.ibm.com>