adsprpc: Modify Remote scalars call apprioriatly to get TZ security key

Add proper remote scalar calls to get TZ security key, which compatible
with dsp process group TZ secure channel call.

Change-Id: I442a7c440deaf1ff8e850894bc3faf9596c7b004
Signed-off-by: Tharun Kumar Merugu <mtharu@codeaurora.org>