sensor: Use getFunc to handle the get sensor reading
sensor: Use getFunc to handle the get sensor reading

Change-Id: If0f3185e7ce1d300be20b58ee5004a58e35c222d
Signed-off-by: Tom Joseph <ccebe3ea0dc9f732d049c731e46285897e145ffb@in.ibm.com>

openbmc/phosphor-host-ipmid,openbmc/phosphor-host-ipmid,openbmc/phosphor-host-ipmid