diag: Add status functionality to Diag over STM command

The Diag over STM command has been enhanced to include a
status capability. Add this functionality to Diag over
STM processing.

Also, the command code for Diag over STM has changed. Make
modifications to support the newly assigned command code.

Change-Id: Ifa371e6d91a2520b0e5d7e672b610a1b8b4991eb
Signed-off-by: Dixon Peterson <dixonp@codeaurora.org>
3 files changed