ARM: dts: imx50-kobo-aura: Enable eKTF2132 touchscreen

The Kobo Aura has an eKTF2132 touchscreen controller.

Although the vendor kernel toggles a reset pin (GPIO5-12) during the
startup sequence, the touchscreen works without it.

Signed-off-by: Jonathan Neuschäfer <j.neuschaefer@gmx.net>
Signed-off-by: Shawn Guo <shawnguo@kernel.org>