ARM: dts: qcom: ipq4019: rename SAW nodes to power-manager

ARM: dts: qcom: ipq4019: rename SAW nodes to power-manager

The SAW2 device is not a regulator. It is a frontend to the PMIC, which
handles voltage control, automatic voltage scaling and low-power states,
Rename SAW2 nodes to 'power-manager', the name which is suggested by
qcom,saw2.yaml

Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Reviewed-by: Konrad Dybcio <konrad.dybcio@linaro.org>
Link: https://lore.kernel.org/r/20240102-saw2-spm-regulator-v7-15-0472ec237f49@linaro.org
Signed-off-by: Bjorn Andersson <andersson@kernel.org>