ARM: dts: msm: add SPMI and PMIC simulator devices for SDM855 RUMI

Add an SPMI controller simulator device for SDM855 RUMI.  Also
add simulator devices for PM855, PM855B, and PM855L which are
associated with the simulated SPMI controller.  This allows
PMIC peripheral devices to be tested before physical PMIC chips
are available.

Change-Id: I076ea069917e4cc39e8b6f9d4cdd0c3e19d3fcf4
Signed-off-by: David Collins <collinsd@codeaurora.org>