dt-bindings: pinctrl: mt8195: Add gpio-line-names property

Add the 'gpio-line-names' property to mt8195-pinctrl, as this will be
used in devicetrees to describe pin names.

Signed-off-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
Reviewed-by: Nícolas F. R. A. Prado <nfraprado@collabora.com>
Link: https://lore.kernel.org/r/20220630110453.186526-1-angelogioacchino.delregno@collabora.com


Signed-off-by: Linus Walleij <linus.walleij@linaro.org>