dt-bindings: arm: qcom: document sc7280 and evoker board

This adds Chromebook Evoker to the yaml.

Signed-off-by: Sheng-Liang Pan <sheng-liang.pan@quanta.corp-partner.google.com>
Acked-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Signed-off-by: Bjorn Andersson <andersson@kernel.org>
Link: https://lore.kernel.org/r/20220902160845.v5.1.Ief93544cd0cbfa412092f5de92de10d59a2a5b3a@changeid