ARM: dts: msm: Add default IPC Router peripheral for MDMCALIFORNIUM

The modem in MDMCALIFORNIUM is currently being unloaded during boot
because no entity is holding the PIL vote for it.

Make modem the default IPC router peripheral so that a vote is held for
the modem, which prevents it from being unloaded.

Change-Id: I56ea76f7040aa68b940de1d9c9a250ce0417ada4
Signed-off-by: Steven Cahail <scahail@codeaurora.org>