msm: clock-krypton: clock entry for debug, etm register save-restore

The Debug and ETM registers need to be saved and restored on power
collapse on msmkrypton. Add support for the required clock that enables
memory mapped access to these registers.

Change-Id: If9e11cc56628da29a4aafe733fd6055c97de4aff
Signed-off-by: Aparna Das <adas@codeaurora.org>