pinctrl: baytrail: Use fallthrough pseudo-keyword

Replace the existing /* fall through */ comments and its variants with
the new pseudo-keyword macro fallthrough[1].

[1] https://www.kernel.org/doc/html/latest/process/deprecated.html?highlight=fallthrough#implicit-switch-case-fall-throughSigned-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>

drivers/pinctrl/intel/pinctrl-baytrail.c

@@ -1372,13 +1372,13 @@ static void byt_irq_unmask(struct irq_data *d)
 	switch (irqd_get_trigger_type(d)) {
 	case IRQ_TYPE_LEVEL_HIGH:
 		value |= BYT_TRIG_LVL;
-		/* fall through */
+		fallthrough;
 	case IRQ_TYPE_EDGE_RISING:
 		value |= BYT_TRIG_POS;
 		break;
 	case IRQ_TYPE_LEVEL_LOW:
 		value |= BYT_TRIG_LVL;
-		/* fall through */
+		fallthrough;
 	case IRQ_TYPE_EDGE_FALLING:
 		value |= BYT_TRIG_NEG;
 		break;