Throw error when invalid MAC Address is set

sdbusplus supports errors on properties, so we can now throw
exceptions on such cases as invalid parameters.

Also changed the journal log levels to ERR.

Tested: Built an image and see invalid parameter errors on values
        like garbage MAC addresses and non-admin MAC Addresses.
Change-Id: I69687bbf34fe51f0c812f40dfc99bb88ce141a2f
Signed-off-by: Gunnar Mills <gmills@us.ibm.com>
2 files changed