ARM: dts: ti/omap: omap3-gta04: use proper touchscreen properties

ARM: dts: ti/omap: omap3-gta04: use proper touchscreen properties

Specify the dimensions of the touchscreen propertly so that
no userspace configuration is needed for it.
Tested with x11 and weston on Debian bookworm.

What is in now is some debris from earlier tries to handle
scaling in kernel:

https://lore.kernel.org/linux-input/cover.1482936802.git.hns@goldelico.com/

Signed-off-by: Andreas Kemnade <andreas@kemnade.info>
Link: https://lore.kernel.org/r/20241205204413.2466775-3-akemnade@kernel.org
Signed-off-by: Kevin Hilman <khilman@baylibre.com>