input: touchpanel: Add Synaptics latest version 2.6 touchpanel driver

This is the reference driver source code for synaptics touch driver,
the version is 2.6.
All the new files are copied from the git commit:
7b6b9d126aca1f371e8abf3ae56d7a5a4e538f13
drivers/input/touchscreen/synaptics_dsx_2.6/synaptics_dsx_active_pen.c
is copied from
kernel/drivers/input/touchscreen/synaptics_dsx/synaptics_dsx_active_pen.c;
drivers/input/touchscreen/synaptics_dsx_2.6/synaptics_dsx_core.c
is copied from
kernel/drivers/input/touchscreen/synaptics_dsx/synaptics_dsx_core.c;
drivers/input/touchscreen/synaptics_dsx_2.6/synaptics_dsx_core.h
is copied from
kernel/drivers/input/touchscreen/synaptics_dsx/synaptics_dsx_core.h;
drivers/input/touchscreen/synaptics_dsx_2.6/synaptics_dsx_fw_update.c
is copied from
kernel/drivers/input/touchscreen/synaptics_dsx/synaptics_dsx_fw_update.c;
drivers/input/touchscreen/synaptics_dsx_2.6/synaptics_dsx_gesture.c
is copied from
kernel/drivers/input/touchscreen/synaptics_dsx/synaptics_dsx_gesture.c;
drivers/input/touchscreen/synaptics_dsx_2.6/synaptics_dsx_i2c.c
is copied from
kernel/drivers/input/touchscreen/synaptics_dsx/synaptics_dsx_i2c.c;
drivers/input/touchscreen/synaptics_dsx_2.6/synaptics_dsx_proximity.c
is copied from
kernel/drivers/input/touchscreen/synaptics_dsx/synaptics_dsx_proximity.c;
drivers/input/touchscreen/synaptics_dsx_2.6/synaptics_dsx_rmi_dev.c
is copied from
kernel/drivers/input/touchscreen/synaptics_dsx/synaptics_dsx_rmi_dev.c;
drivers/input/touchscreen/synaptics_dsx_2.6/synaptics_dsx_rmi_hid_i2c.c
is copied from
kernel/drivers/input/touchscreen/synaptics_dsx/synaptics_dsx_rmi_hid_i2c.c;
drivers/input/touchscreen/synaptics_dsx_2.6/synaptics_dsx_spi.c
is copied from
kernel/drivers/input/touchscreen/synaptics_dsx/synaptics_dsx_spi.c;
drivers/input/touchscreen/synaptics_dsx_2.6/synaptics_dsx_test_reporting.c
is copied from
kernel/drivers/input/touchscreen/synaptics_dsx/synaptics_dsx_test_reporting.c
drivers/input/touchscreen/synaptics_dsx_2.6/synaptics_dsx_video.c
is copied from
kernel/drivers/input/touchscreen/synaptics_dsx/synaptics_dsx_video.c
include/linux/input/synaptics_dsx_v2_6.h
is copied from
kernel/include/linux/input/synaptics_dsx.h

Change-Id: Ifda2c38ca5b4a82c3363d8c59ae9da3839568e82
Signed-off-by: Mao Li <maol@codeaurora.org>