phosphor-ipmi-host: Create system-specific hardcoded.yaml file

Witherspoon has 2-rotor fans, while Swift has single-rotor fans.
Move the sensors for the 2nd rotor to a witherspoon yaml file.
In the future, any system-specific sensors can be added to the
witherspoon/swift_hardcoded.yaml file

Tested: Built swift and witherspoon and verified only witherspoon
        had the new witherspoon_hwmon_sensors.hardcoded.yaml in the
        build directory.

Change-Id: Ie9d0719b17eaa6a3e6cb9457deca32f7f727e546
Signed-off-by: Adriana Kobylak <anoo@us.ibm.com>
3 files changed