soc: qcom: socinfo: Change offset of image OEM attribute

There is a requirement, for diag command handler, that needs
the separator between image variant and image OEM to be shown
as part of OEM value in sysfs. So change the relevant offset
and size to include this information in image oem sysfs
attribute.

CRs-Fixed: 1086976
Change-Id: Iae12fa648df17dddd48f3a71e94d06c2c3b03277
Signed-off-by: Imran Khan <kimran@codeaurora.org>
Signed-off-by: Prasad Sodagudi <psodagud@codeaurora.org>