pinctrl: mediatek: fix static checker warning caused by EINT_NA

EINT_NA is an u16 number, so it should be U16_MAX instead of -1
to fix up drivers/pinctrl/mediatek/pinctrl-paris.c:732 mtk_gpio_to_irq()
warn: impossible condition (desc->eint.eint_n == -1) => (0-u16max == (-1))

Also happens in
drivers/pinctrl/mediatek/pinctrl-paris.c:749 mtk_gpio_set_config()
warn: impossible condition (desc->eint.eint_n == -1) => (0-u16max == (-1))

drivers/pinctrl/mediatek/pinctrl-moore.c:479 mtk_gpio_to_irq()
warn: impossible condition (desc->eint.eint_n == -1) => (0-u16max == (-1))

drivers/pinctrl/mediatek/pinctrl-moore.c:496 mtk_gpio_set_config()
warn: impossible condition '(desc->eint.eint_n == -1) => (0-u16max == (-1))

Fixes: 6561859b067f ("pinctrl: mediatek: add eint support to MT8183 pinctrl driver")
Reported-by: Dan Carpenter <[e-mail]>
Signed-off-by: Sean Wang <[e-mail]>
Signed-off-by: Linus Walleij <[e-mail]>

drivers/pinctrl/mediatek/pinctrl-mtk-common-v2.h

···
 #define MTK_PULLDOWN   0
 #define MTK_PULLUP     1
 
-#define EINT_NA	-1
+#define EINT_NA	U16_MAX
 
 #define PIN_FIELD_CALC(_s_pin, _e_pin, _i_base, _s_addr, _x_addrs,      \
 		       _s_bit, _x_bits, _sz_reg, _fixed) {		\