Input: ts4800-ts - switch to using polled mode of input devices

We have added polled mode to the normal input devices with the intent of
retiring input_polled_dev. This converts ts4800-ts driver to use the
polling mode of standard input devices and removes dependency on
INPUT_POLLDEV.

Link: https://lore.kernel.org/r/20191017204217.106453-4-dmitry.torokhov@gmail.com
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>

Input: ts4800-ts - use devm_platform_ioremap_resource()

devm_platform_ioremap_resource() internally have platform_get_resource()
and devm_ioremap_resource() in it. So instead of calling them separately
use devm_platform_ioremap_resource() directly.

Signed-off-by: Mukesh Ojha <mojha@codeaurora.org>
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>

Input: ts4800-ts - add missing of_node_put after calling of_parse_phandle

of_node_put needs to be called when the device node which is got
from of_parse_phandle has finished using.

Signed-off-by: Peter Chen <peter.chen@nxp.com>
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>

Input: add touchscreen support for TS-4800

On this board, the touchscreen, an ads7843, is not handled directly by
Linux but by a companion FPGA. This FPGA is memory-mapped and the IP
design is very similar to the mk712.

This commit adds the support for this IP.

Signed-off-by: Damien Riegel <damien.riegel@savoirfairelinux.com>
Acked-by: Rob Herring <robh@kernel.org>
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>