msm: spm_devices: Update FTS/Phase APIs to support multiple cluster/rails.

On newer architectures which have multiple clusters and cpu-rails,
the fts and phase set apis could be called from one cluster and
executed on another clusters cpu. This could result in the wrong
fts/phase settings.
Provide the cpu number from the calling core to make sure that the
fts/phase change api acts on the calling cpu's voltage control
device.

Change-Id: Ifccda336fa5944435d8fbbe19188ab25d3e82c76
Signed-off-by: Karthik Parsha <kparsha@codeaurora.org>