ARM: dts: msm: enable audio nodes for msmgold

Include audio specific DT files in dtsi rather than dts.
This would help APQ/RCM flavors which include the MTP/CDP
dtsi files. Else they also need to include audio DT files.
Also clean up external codec DT file for GPIO not used by
audio.

Change-Id: I77df7c38cd60d560f73cecdb9329545e0344f836
Signed-off-by: Laxminath Kasam <lkasam@codeaurora.org>