qcom: spm: Support SAW4 power configuration

SAW4 hardware needs few additional bits to be configured for SPM nodes
to enter sleep. Program additional bits to enable low power modes.

Change-Id: I1c35f0cea17a6ad6738249583bebf1bcab36989a
Signed-off-by: Archana Sathyakumar <asathyak@codeaurora.org>