dt-bindings: arm: qcom: Document qcom,sc7280-crd board

Document the qcom,sc7280-crd board based off sc7280 SoC,
The board is also known as hoglin in the Chrome OS builds,
so document the google,hoglin compatible as well.

Signed-off-by: Rajendra Nayak <quic_rjendra@quicinc.com>
Reviewed-by: Matthias Kaehlcke <mka@chromium.org>
Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>
Link: https://lore.kernel.org/r/1638185497-26477-2-git-send-email-quic_rjendra@quicinc.com