arm64: dts: allwinner: a64: olinuxino: Enable audio

Enable the audio hardware on the Olimex A64-OLinuXino board family.
Tested on the A64-OLinuXino-2Ge8G-IND variant.

Signed-off-by: Philip Rinn <rinni@inventati.org>
Acked-by: Samuel Holland <samuel@sholland.org>
Signed-off-by: Jernej Skrabec <jernej.skrabec@gmail.com>
Link: https://lore.kernel.org/r/20220407155145.10891-1-rinni@inventati.org