GPIODV_18 entry was missing in the original driver push.

Fixes: 0f15f500 ("pinctrl: meson: Add GXL pinctrl definitions")
Signed-off-by: NNeil Armstrong <narmstrong@baylibre.com>
Reviewed-by: NJerome Brunet <jbrunet@baylibre.com>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>