ARM: dts: msm: Add smp2p sleepstate node for sm8150

Add device node for the smp2p sleepstate entry and the device node for
the sm2p sleep driver to notify dsps of apps power state changes.

Change-Id: I750fbaf3f12fc3275b72346ea1bffeaad9e0230e
Signed-off-by: Chris Lew <clew@codeaurora.org>