Change default name for the IPMI KCS channel

By default the 'kcsbridged.service' of the kcsbridge utility
creates an IPMI channel on a Dbus with a name 'ipmi_kcs3'.
To be able to use it 'channel_config.json' file should
have the same name for the KCS channel.

(From meta-phosphor rev: 73cf55f14deca23f2214578eb2c2661a1932d9da)

Signed-off-by: Konstantin Aladyshev <aladyshev22@gmail.com>
Change-Id: Ic483a7da0cf5d34d81f955da53561e14ba210f97
Signed-off-by: Andrew Geissler <geissonator@yahoo.com>