arm64: dts: qcom: Add base qcs6490-rb3gen2 board dts

Add DTS for Qualcomm qcs6490-rb3gen2 board which uses
QCS6490 SoC. This adds debug uart and usb support along
with regulators found on this board.

Co-developed-by: Naina Mehta <quic_nainmeht@quicinc.com>
Signed-off-by: Naina Mehta <quic_nainmeht@quicinc.com>
Signed-off-by: Komal Bajaj <quic_kbajaj@quicinc.com>
Reviewed-by: Konrad Dybcio <konrad.dybcio@linaro.org>
Reviewed-by: Caleb Connolly <caleb.connolly@linaro.org>
Link: https://lore.kernel.org/r/20231129065816.26409-4-quic_kbajaj@quicinc.com


Signed-off-by: Bjorn Andersson <andersson@kernel.org>