dt-bindings: arm: qcom: Add sc7180 Chromebook board bindings

dt-bindings: arm: qcom: Add sc7180 Chromebook board bindings

This copy-pastes compatibles from sc7180-based boards from the device
trees to the yaml file so that `make dtbs_check` will be happy.

NOTES:
- I make no attempt to try to share an "item" for all sc7180 based
  Chromebooks. Because of the revision matching scheme used by the
  Chromebook bootloader, at times we need a different number of
  revisions listed.
- Some of the odd entries in here (like google,homestar-rev23 or the
  fact that "Google Lazor Limozeen without Touchscreen" changed from
  sku5 to sku6) are not typos but simply reflect reality.
- Many revisions of boards here never actually went to consumers, but
  they are still in use within various companies that were involved in
  Chromebook development. Since Chromebooks are developed with an
  "upstream first" methodology, having these revisions supported with
  upstream Linux is important. Making it easy for Chromebooks to be
  developed with an "upstream first" methodology is valuable to the
  upstream community because it improves the quality of upstream and
  gets Chromebooks supported with vanilla upstream faster.

One other note here is that, though the bootloader effectively treats
the list of compatibles in a given device tree as unordered, some
people would prefer future boards to list higher-numbered revisions
first in the list. Chromebooks here are not changing and typically
list lower revisions first just to avoid churn.

Signed-off-by: Douglas Anderson <dianders@chromium.org>
Reviewed-by: Matthias Kaehlcke <mka@chromium.org>
Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>
Link: https://lore.kernel.org/r/20220520143502.v4.3.I9804fcd5d6c8552ab25f598dd7a3ea71b15b55f0@changeid