Clean up GPU configs in DM

Remove wide and narrow, adjust remaining configs to match the new CPU
configs, and fix several formatting problems in the help output.

Bug: skia:
Change-Id: I0946ac407d88a922e7f62220e7f4b39ae8c2e469
Reviewed-on: https://skia-review.googlesource.com/131000
Reviewed-by: Brian Salomon <bsalomon@google.com>
Reviewed-by: Mike Klein <mtklein@google.com>
Commit-Queue: Brian Osman <brianosman@google.com>
2 files changed