Input: mms114 - drop platform data and use generic APIs

The MMS114 platform data has no in-tree users, so drop it.

Switch to using the standard touchscreen properties via
touchscreen_parse_properties(), and move the old DT parsing code
to use device_property_*() APIs.

Finally, use touchscreen_report_pos to report x/y coordinates
and drop the custom x/y inversion code.

Signed-off-by: Simon Shields <simon@lineageos.org>
Reviewed-by: Rob Herring <robh@kernel.org>
Reviewed-by: Andi Shyti <andi.shyti@samsung.com>
Tested-by: Andi Shyti <andi.shyti@samsung.com>
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>