diag: Add generic diag interface

This new interface will allow diag clients to pull data into
the client context. The client can then process the data in any
manner they desire.

Change-Id: Ia76564c4cc985013533a759bc2b398dbee13445a
Signed-off-by: Shalabh Jain <shalabhj@codeaurora.org>
4 files changed