input: synaptics_i2c_rmi4: Move touch driver and fix issues

Move the synaptics touchscreen driver to drivers/input/touchscreen
and fix checkpatch issues.

Change-Id: I78dcc2f540ca78e192b4570e414a8802e8982945
Signed-off-by: Amy Maloche <amaloche@codeaurora.org>
Signed-off-by: Himanshu Aggarwal <haggarwa@codeaurora.org>
Signed-off-by: Shantanu Jain <shjain@codeaurora.org>