pinctrl: meson-gxbb: add the missing SDIO interrupt pin

This adds the SDIO interrupt pin which can be used by sd_emmc_a.

Signed-off-by: Martin Blumenstingl <martin.blumenstingl@googlemail.com>
Suggested-by: Neil Armstrong <narmstrong@baylibre.com>

Fixes: 29885a65 ("pinctrl: meson-gxbb: add the pins for the
SDIO/sd_emmc_a controller")
Acked-by: Kevin Hilman <khilman@baylibre.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>