ARM: dts: msm: add device tree support for sdw2500

Add device tree support for sdw2500. This implementation
is based on snapshot of the sdw2500 device tree from
msm-3.18 commit bba04f9343311
("ARM: dts: msm: add synaptics touch firmware for wearables").

Change-Id: I6fdd6eb1813e1fc6d4c1b5fac8aa261e18d3e53a
Signed-off-by: Manjunatha Madana <mamanj@codeaurora.org>