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-through

Signed-off-by: Gustavo A. R. Silva <[e-mail]>
Signed-off-by: Andy Shevchenko <[e-mail]>

drivers/pinctrl/intel/pinctrl-baytrail.c

···
 	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;