util/docker: Update Makefile to improve shell access

- Create a new target, docker-jenkins-attach, to access the running
jenkins server
- Update docker-shell target to set term & size.

Change-Id: Ifa67afb62d4a216281ebece405e9b26fd4d14622
Signed-off-by: Martin Roth <gaumless@gmail.com>
Reviewed-on: https://review.coreboot.org/27494
Reviewed-by: Werner Zeh <werner.zeh@siemens.com>
Reviewed-by: Marc Jones <marc@marcjonesconsulting.com>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
1 file changed