arm64: dts: allwinner: a64: Add I2S2 node

Add the I2S2 node connected to the HDMI interface.

Signed-off-by: Jernej Skrabec <jernej.skrabec@siol.net>
Signed-off-by: Marcus Cooper <codekipper@gmail.com>
Signed-off-by: Clément Péron <peron.clem@gmail.com>
Signed-off-by: Maxime Ripard <maxime@cerno.tech>
Acked-by: Chen-Yu Tsai <wens@csie.org>
Link: https://lore.kernel.org/r/20201030144648.397824-13-peron.clem@gmail.com