power: supply: adp5061: show unknown capacity_level as text

adp5061_get_battery_status() only defined show chg_status <= 4, others will
be show as '-1731902199' from /sys/class/power_supply/xx/capacity_level.
switch to show them as 'Unknown'.

Signed-off-by: Wei Yongjun <[e-mail]>
Acked-by: Michael Hennerich <[e-mail]>
Signed-off-by: Sebastian Reichel <[e-mail]>

drivers/power/supply/adp5061.c

···
 	case 0x4: /* VBAT_SNS > VWEAK */
 		val->intval = POWER_SUPPLY_CAPACITY_LEVEL_NORMAL;
 		break;
+	default:
+		val->intval = POWER_SUPPLY_CAPACITY_LEVEL_UNKNOWN;
+		break;
 	}
 
 	return ret;