soc: qcom: spm: remove driver-internal structures from the driver API

Move internal SPM driver structures to the driver itself, removing them
from the public API. The CPUidle driver doesn't use them at all.

Reviewed-by: Konrad Dybcio <konrad.dybcio@linaro.org>
Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Link: https://lore.kernel.org/r/20240102-saw2-spm-regulator-v7-4-0472ec237f49@linaro.org


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