ARM: dts: msm: Add rpm notification bit support for msmzirc

msmzirc target has a SLP_CMD_MODE that could be set for rpm
notification. Add this bit for the target and remove
rpm notification from spm sequence.

Change-Id: I301191052b1eabb839fe93e3f1fb04ab5a9b3675
Signed-off-by: Archana Sathyakumar <asathyak@codeaurora.org>