arm64: dts: meson: p230-q200: add internal DAC support

Add the necessary bits to support the internal audio DAC the p230/q200
reference design derivated boards. The output of this DAC is provided
on the 3.5mm jack connector

Signed-off-by: Jerome Brunet <jbrunet@baylibre.com>
Signed-off-by: Kevin Hilman <khilman@baylibre.com>
Link: https://lore.kernel.org/r/20200506221656.477379-3-jbrunet@baylibre.com