dt-bindings: reset: meson: add gxl internal dac reset

Add the reset line of the internal DAC found on the amlogic gxl SoC family

Signed-off-by: Jerome Brunet <jbrunet@baylibre.com>
Reviewed-by: Neil Armstrong <narmstrong@baylibre.com>
Signed-off-by: Philipp Zabel <p.zabel@pengutronix.de>