swift: Add tmp275 ambient sensor

Swift has 3 ambient temperature sensors, the tmp275 will be labeled as
`ambient0` and initially use the same warn/crit temperature
configurations as Witherspoon.

Tested:
    Built image that contained the config file

Change-Id: Ia2b70152527ad639515a1bb31cd2c510f9f26595
Signed-off-by: Matthew Barth <msbarth@us.ibm.com>
2 files changed