Patch merged into coreboot/master: util/docker: Update makefile target names

the following patch was just integrated into master:
commit 9ee70ce5873e7f93c60ea969b388d4027ae6aba8
Author: Martin Roth 
Date:   Fri Dec 30 16:26:13 2016 -0700

util/docker: Update makefile target names

- Use dashes instead of underscores for consistency and to match other
    coreboot targets
    - Fix a couple of places where old target names were referenced
    - Remove double 'help' target from .PHONEY target list

Change-Id: I3b464ebf74653a8cc880e982316fd883757ec728
    Signed-off-by: Martin Roth 
    Reviewed-on: https://review.coreboot.org/18000
    Tested-by: build bot (Jenkins)
    Reviewed-by: Paul Menzel 
    Reviewed-by: Patrick Georgi

See https://review.coreboot.org/18000 for details.

-gerrit