pinctrl: rockchip: Simplify pin_to_bank equation

If (b->pin_base + b->nr_pins - 1) < pin is true, pin >= b->pin_base is always
true because b->nr_pins is never less than 0.
Thus this patch simplify the equation.
Signed-off-by: Axel Lin <axel.lin@ingics.com>
Acked-by: Heiko Stuebner <heiko@sntech.de>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

drivers/pinctrl/pinctrl-rockchip.c

@@ -186,8 +186,7 @@ static struct rockchip_pin_bank *pin_to_bank(struct rockchip_pinctrl *info,
 {
 	struct rockchip_pin_bank *b = info->ctrl->pin_banks;
 
-	while ((pin >= b->pin_base) &&
-			((b->pin_base + b->nr_pins - 1) < pin))
+	while (pin >= (b->pin_base + b->nr_pins))
 		b++;
 
 	return b;