input: synaptics: Register sysfs entries with i2c client

Register sysfs entries with i2c client instead of input
device.  This is standardized across touchscreen drivers.

This patch is propagated from msm-3.4 kernel.
(commit: 4d54ac4ce9511ff6d3dff2804e9794a109bbe529
input: synaptics: Register sysfs entries with i2c client)

Change-Id: I90140d2cd33287f7b090b5ed5275aa3b75999d0b
Signed-off-by: Amy Maloche <amaloche@codeaurora.org>