ARM: dts: msm: add pmxprairie and PM8150B PMIC devices for sdxprairie

Add top level SPMI slave devices for pmxprairie and PM8150B PMICs.
Also add some of the peripheral devices within the SPMI slave
devices.

Change-Id: Ibe33ba49b448cc03965d81dbd827092877b0487a
Signed-off-by: David Collins <collinsd@codeaurora.org>