msm: ADSPRPC: Root process creation in Sensors PD

Support root process creation in sensors PD and share context
bank for all sensors processes.

Change-Id: I17859f6b5c9ec8ae6a325172ddfab9860bf896f5
Acked-by: Himateja Reddy <hmreddy@qti.qualcomm.com>
Signed-off-by: Tharun Kumar Merugu <mtharu@codeaurora.org>