msm: Add image version reporting node into socinfo

Get smem block, which stores image version strings for all images and
export those strings to userspace through sysfs entries.

Change-Id: Ifb1a3d0670e6199e0d0d8da752c17bdda370bfe2
Signed-off-by: Yulian Shandorov <jshandorov@codeaurora.org>