riscv: dts: allwinner: d1: Add GPADC node

This patch adds declaration of the general purpose ADC for D1
and T113s SoCs.

Signed-off-by: Maksim Kiselev <bigunclemax@gmail.com>
Acked-by: Jernej Skrabec <jernej.skrabec@gmail.com>
Link: https://lore.kernel.org/r/20230619154252.3951913-5-bigunclemax@gmail.com


Signed-off-by: Jernej Skrabec <jernej.skrabec@gmail.com>