dt-bindings: arm: msm: Add support for jtag mm

Jtag mm driver saves ETM registers before power collapse and
restores it after resume.

Change-Id: I238ad710a715ca306742cc23ab8e6d1dc9431016
Signed-off-by: Mulu He <muluhe@codeaurora.org>
Signed-off-by: Tingwei Zhang <tingwei@codeaurora.org>