Input: pm8941-pwrkey - disable wakeup for resin by default

Input: pm8941-pwrkey - disable wakeup for resin by default

'Resin' (*Res*et *In*put) is usually connected to a volume down button
on devices, which is usually not expected to wake up the device from
suspend.

On the other hand, pwrkey should keep wakeup on. So do not enable wakeup
for resin unless the "wakeup-source" property is specified in
devicetree.

Note, that this does change behavior by turning off wakeup by default
for 'resin' and requiring a new dt property to be added to turn it on
again. But since this is not expected behavior in the first place, and
most users will not expect this, I'd argue this change is acceptable.

Signed-off-by: Luca Weiss <luca@lucaweiss.eu>
Reviewed-by: Neil Armstrong <neil.armstrong@linaro.org>
Link: https://lore.kernel.org/r/20250909-resin-wakeup-v1-2-46159940e02b@lucaweiss.eu
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>