arm64: dts: meson-g12a: fix reset controller compatible

This fixes the following DT schemas check errors:
meson-g12a-u200.dt.yaml: reset-controller@1004: compatible:0: 'amlogic,meson-g12a-reset' is not one of ['amlogic,meson8b-reset', 'amlogic,meson-gxbb-reset', 'amlogic,meson-axg-reset']
meson-g12a-sei510.dt.yaml: reset-controller@1004: compatible:0: 'amlogic,meson-g12a-reset' is not one of ['amlogic,meson8b-reset', 'amlogic,meson-gxbb-reset', 'amlogic,meson-axg-reset']

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