arm64: dts: qcom: pm660(l): Add base dts files

Add base DTS files for pm660(l) along with GPIOs, power-on and
rtc nodes.

Signed-off-by: Konrad Dybcio <konradybcio@gmail.com>
Link: https://lore.kernel.org/r/20200622192558.152828-4-konradybcio@gmail.com


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