ARM: dts: qcom: pm8226: add PON device node along with resin sub-node

The PON (Power On) device in PM8226 supports both the power key and
resin (reset input).
The reset input is usually connected to a physical volume up/down button.

Signed-off-by: Rayyan Ansari <rayyan@ansari.sh>
Reviewed-by: Luca Weiss <luca@z3ntu.xyz>
Signed-off-by: Bjorn Andersson <andersson@kernel.org>
Link: https://lore.kernel.org/r/20221223193403.781355-3-rayyan@ansari.sh