ARM: dt: msm: add more wsa881x devices for MSM8996 targets

MSM8996 based targets supports different versions of wsa881x
chipset. Add a list of all additional devices which might
be supported for the target. Create a separate DTSI file
to define the list of different wsa881x devices supported.

Change-Id: I38a90787bbbb483d24fe9f64b833b54c167fc008
Signed-off-by: Banajit Goswami <bgoswami@codeaurora.org>