dt-bindings: pinctrl: mediatek,pinctrl-mt6795: Fix interrupt count

dt-bindings: pinctrl: mediatek,pinctrl-mt6795: Fix interrupt count

The document currently states a maximum of 1 interrupt, but the DT
has 2 specified causing a dtbs_check error. Replace the maximum limit
with a minimum and add per-interrupt descriptions to pass the check.

Fixes: 81557a71564a ("dt-bindings: pinctrl: Add MediaTek MT6795 pinctrl bindings")
Suggested-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
Signed-off-by: Yassine Oudjana <y.oudjana@protonmail.com>
Reviewed-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
Acked-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Link: https://lore.kernel.org/r/20221028153505.23741-6-y.oudjana@protonmail.com
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>