linux-imx

MLK-14801 input: touch: ads7846: fix the pressure_max setting

For the touch pressure_max, if dts has no property "ti,pressure-max"
or this property is config to value 0, then default use 65535 as
the max pressure value. otherwise, in the latest xwayland rootfs,
will meet the following issue:

[21:44:34.302] input device 'ADS7846 Touchscreen', /dev/input/event3 is tagged by udev as: Touchscreen
[21:44:34.302] kernel bug: Device 'ADS7846 Touchscreen' has min == max on ABS_PRESSURE
[21:44:34.302] input device 'ADS7846 Touchscreen', /dev/input/event3 was rejected.
[21:44:34.302] failed to create input device '/dev/input/event3'

Reviewed-by: Fugang Duan <fugang.duan@nxp.com>
Signed-off-by: Haibo Chen <haibo.chen@nxp.com>
(cherry picked from commit 0bb15e676cb74739291c9054411a28cad4e36f34)
Signed-off-by: Vipul Kumar <vipul_kumar@mentor.com>