ARM: dts: msm: Disable modem pil loading from mproc code for MSM8937

The smd and ipc-router drivers trigger the loading of the modem via
calls to subsystem_get. We now disable this functionality for 8937
since power on of the modem is handled by the peripheral manager in
userspace.

Change-Id: I3dc4625cdcb8988c99d0a83139bfe46c28226ad3
Signed-off-by: Arun Kumar Neelakantam <aneela@codeaurora.org>