arm64: dts: qcom: Add PM6125 PMIC

This PMIC is commonly used on boards with an SM6125 SoC and looks very
similar in layout to the PM6150.

Downstream declares more nodes to be available, but these have been
omitted from this patch: the pwm/lpg block is unused on my reference
device making it impossible to test/validate, and the spmi-clkdiv does
not have a single device-tree binding using this driver yet, hence
inclusion is better postponed until ie. audio which uses these clocks is
brought up.

Signed-off-by: Marijn Suijten <marijn.suijten@somainline.org>
Reviewed-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@somainline.org>
Reviewed-by: Konrad Dybcio <konrad.dybcio@somainline.org>
Signed-off-by: Bjorn Andersson <andersson@kernel.org>
Link: https://lore.kernel.org/r/20220926190148.283805-4-marijn.suijten@somainline.org