tidy up chromeos_setup.sh

- remove unused alex
- streamline Link's config
- remove misleading Daisy config:
  1) armv7=1 does nothing.  We meant to type arm_version=7 here.
  2) arm_neon=1 does nothing unless arm_version == 7.
  3) arm_thumb=0 is the default when arm_version <= 7.
  4) skia_arch_width=32 is the default when skia_arch_type=arm.

I'd just fix this to make Daisy arm_version=7 and arm_neon=1 (and
arm_thumb=1, which I'm going to separately make the default for
arm_version=7), but there are known color-order bugs with our
NEON procs that would make Daisy start pushing bad images to
Gold.  Going to take baby steps here...

BUG=skia:1843

Review URL: https://codereview.chromium.org/1051253002
1 file changed