console-image: add connman for network configuration

Use connman for configuring network interfaces instead of having
different systemd and sysvinit based network configuration tools.
This results in a single configuration for both init systems and
also avoids duplication of network configuration functionality.

 * We already support core-image-sato which contains connman so
   better add it in console-image too.

JIRA: http://jira.alm.mentorg.com:8080/browse/SB-4013

Signed-off-by: Yasir-Khan <yasir_khan@mentor.com>
packagegroup-core-boot: drop sysvinit bits for network config

Drop sysvinit bits that are responsible for configuring the network
interfaces in favor of the connman based network configuration.

Signed-off-by: Yasir-Khan <yasir_khan@mentor.com>
Merge pull request #383 from Yasir-Khan/connman

Switch to connman for network configuration