hwmon: (adt7462) Mark expected switch fall-throughs

In preparation to enabling -Wimplicit-fallthrough, mark switch cases
where we are expecting to fall through.

Warning level 3 was used: -Wimplicit-fallthrough=3
Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>

drivers/hwmon/adt7462.c

@@ -448,6 +448,7 @@ static const char *voltage_label(struct adt7462_data *data, int which)
 		case 3:
 			return "+1.5V";
 		}
+		/* fall through */
 	case 2:
 		if (!(data->pin_cfg[1] & ADT7462_PIN22_INPUT))
 			return "+12V3";
@@ -505,6 +506,7 @@ static const char *voltage_label(struct adt7462_data *data, int which)
 		case 3:
 			return "+1.5";
 		}
+		/* fall through */
 	case 11:
 		if (data->pin_cfg[3] >> ADT7462_PIN28_SHIFT ==
 					ADT7462_PIN28_VOLT &&
@@ -542,6 +544,7 @@ static int voltage_multiplier(struct adt7462_data *data, int which)
 		case 3:
 			return 7800;
 		}
+		/* fall through */
 	case 2:
 		if (!(data->pin_cfg[1] & ADT7462_PIN22_INPUT))
 			return 62500;
@@ -599,6 +602,7 @@ static int voltage_multiplier(struct adt7462_data *data, int which)
 		case 3:
 			return 7800;
 		}
+		/* fall through */
 	case 11:
 	case 12:
 		if (data->pin_cfg[3] >> ADT7462_PIN28_SHIFT ==