ARM: dts: msm: enable touch controller for 8939

8939 CDP supports two Synaptics touchscreen controllers : S3202
and S3408. Add proper device tree configuration to bring up these
touch panels.

Change-Id: Ia6c1ad4c86f5548423843588d33097401314de62
Signed-off-by: Himanshu Aggarwal <haggarwa@codeaurora.org>
Signed-off-by: Shantanu Jain <shjain@codeaurora.org>