msm: ADSPRPC: Add ioctl for remote process creation

The new ioctl exposes mechanism for user processes to create
a new process on the remote end when the device is opened.

Change-Id: Id27c7572d3bdd5ecfb899ac20dd237ab25f5a161
Acked-by: Sathish Ambley <sambley@qti.qualcomm.com>
Signed-off-by: Liam Mark <lmark@codeaurora.org>