dts: sdm845: replace with upstream DTS

Import sdm845.dtsi from upstream, as well as the upstream DTS files for
the db845c and Samsung starqltechn. Delete the old board files.

Taken from kernel tag v6.7

Reviewed-by: Neil Armstrong <neil.armstrong@linaro.org>
Reviewed-by: Sumit Garg <sumit.garg@linaro.org>
Signed-off-by: Caleb Connolly <caleb.connolly@linaro.org>