ARM: dts: msm: add support for SMP2P shutdown ack from modem

Add the device tree entry to define the SMP2P interface for shutdown
acknowledgment from modem after SSCTL command is sent from APPS to
MPSS. Also define the correct SSCTL instance ID to register the
SSCTL QMI service.

Change-Id: Ic63ada9e14b22ab1c995f50a0b9d65218223d49d
Signed-off-by: Abinaya P <abinayap@codeaurora.org>