coresight: Add snapshot of Coresight Dbgui driver

Add snapshot for coresight Dbgui driver from msm-3.18
commit cf126d1be1a("ANDROID: sdcardfs: Add option to
not link obb"). Make necessary change to adopt coresight
framework change.

Change-Id: I3cf911f20b79f88cbc6482304fd6f43989aa881a
Signed-off-by: Yuanfang Zhang <zhangyuanfang@codeaurora.org>