ARM: dts: msm: Add imem for MSMSKUNK

Add required device tree node for imem and entry for
memory dump table. This will enable memory dump collection
in case of a crash.

CRs-Fixed: 1053067
Change-Id: I2966c5cb0f254b80bc0508f6f22686323d9a0b4f
Signed-off-by: Satyajit Desai <sadesai@codeaurora.org>