The recently added AP15C dts file only differs by the definition of the
reset button. Unify the shared definition into a dtsi to reduce code
duplication.
Signed-off-by: Christoph Krapp <achterin@gmail.com>
Tested-by: Martin Blumenstingl <martin.blumenstingl@googlemail.com>
Link: https://github.com/openwrt/openwrt/pull/16998
Signed-off-by: Hauke Mehrtens <hauke@hauke-m.de>
