arm64: dts: rockchip: Add saradc and adc buttons to Khadas Edge 2 and enable tsadc

This commit enables tsadc, saradc and the
function button on saradc line for Khadas Edge 2.

Signed-off-by: Muhammed Efe Cetin <efectn@protonmail.com>
Link: https://lore.kernel.org/r/03feaafefd0c13268ba1630251558749654a567d.1708381247.git.efectn@protonmail.com


Signed-off-by: Heiko Stuebner <heiko@sntech.de>