pinctrl: meson-gx: fix GPIO_TEST_N and GPIOCLK_ groups

The GPIO_TEST_N was in the wrong pmx group table, move it back with the AO
groups, GPIODV_18 was missing, add it back, and finally the GPIOCLK_*
group names were missing.

Signed-off-by: Neil Armstrong <narmstrong@baylibre.com>