arm64: dts: meson: g12a: add i2c nodes

Add pinctrl and nodes for i2c support on amlogic g12a

Signed-off-by: Guillaume La Roque <glaroque@baylibre.com>
Signed-off-by: Jerome Brunet <jbrunet@baylibre.com>
Signed-off-by: Kevin Hilman <khilman@baylibre.com>