arm64: dts: meson-g12a-sei510: Add ADC Key and BT support

Add support for the :
- ADC Touch key
- Bluetooth Module on UART A

Signed-off-by: Neil Armstrong <narmstrong@baylibre.com>
Acked-by: Martin Blumenstingl <martin.blumenstingl@googlemail.com>
Signed-off-by: Kevin Hilman <khilman@baylibre.com>