pinctrl: mediatek: Fix new design debounce issue

Calculate the true offset of eint according to index.

Fixes: 3ef9f710 ("pinctrl: mediatek: Add EINT support for multiple addresses")
Signed-off-by: Hao Chang <ot_chhao.chang@mediatek.com>
Signed-off-by: Qingliang Li <qingliang.li@mediatek.com>
Link: https://lore.kernel.org/20250422075216.14073-1-ot_chhao.chang@mediatek.com


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