gpio: pca953x: fix gpio input on gpio offsets >= 8

This change fixes a regression introduced by commit
f5f0b7aa8 (gpio: pca953x: make the register access by GPIO bank)

When the pca953x driver was converted to using 8-bit reads/writes
the bitmask in pca953x_gpio_get_value wasn't adjusted with a
modulus BANK_SZ and consequently looks at the wrong bits in the
input register.

Signed-off-by: Andrew Ruder <[e-mail]>
Reviewed-by: Gregory CLEMENT <[e-mail]>
Signed-off-by: Linus Walleij <[e-mail]>

drivers/gpio/gpio-pca953x.c

···
 		return 0;
 	}
 
-	return (reg_val & (1u << off)) ? 1 : 0;
+	return (reg_val & (1u << (off % BANK_SZ))) ? 1 : 0;
 }
 
 static void pca953x_gpio_set_value(struct gpio_chip *gc, unsigned off, int val)