[baremetal] reclass: Fix class order for common

[baremetal] reclass: Fix class order for common

Inheriting classes in the wrong order led to params being silently
overriden by defaults in the system reclass classes, leaving
some mismatched values between the controller nova config and the
compute conunterpart (e.g. metadata_password had different values).

Always inherit the common class first, so scenario-specific config
is applied on top.

NOTE: {dhcp,single}_nic are not used for mas|kvm|cmp nodes, but they
are referenced in inherited classes, so keep them for now.

Change-Id: I6cb90d5c832ffc8ab731bd9e3cd38ede858dba5c
Signed-off-by: Alexandru Avadanii <Alexandru.Avadanii@enea.com>
Signed-off-by: Michael Polenchuk <mpolenchuk@mirantis.com>