pinctrl: meson: fix gpio request disabling other modes

The pinctrl_gpio_request is called with the "full" gpio number, already
containing the base, then meson_pmx_request_gpio is then called with the
final pin number.
Remove the base addition when calling meson_pmx_disable_other_groups.

Fixes: 6ac73095 ("pinctrl: add driver for Amlogic Meson SoCs")
CC: Beniamino Galvani <b.galvani@gmail.com>
Signed-off-by: Neil Armstrong <narmstrong@baylibre.com>
Acked-by: Kevin Hilman <khilman@baylibre.com>
Acked-by: Beniamino Galvani <b.galvani@gmail.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>