ARM: dts: msm: Add CNSS platform driver support

Add CNSS platform driver support for MDM9630.
Platform driver takes care of following items for QCA6174.
    1. Bring-up QCA6174
    2. Subsystem Restart support

Also add Always-on voltage regulator to regulator device tree.

Change-Id: I763c590b30cd44c5258a7a6670b6186f76890062
Signed-off-by: Prashanth Bhatta <bhattap@codeaurora.org>