Better determination of power status

Attached is a patch that relaxes the determination charging power
supplies from 'Mains' to !'Battery'  per allowable types exposed by the
drivers/power/power_supply_sysfs.c driver

	static char *type_text[] = {
		"Unknown", "Battery", "UPS", "Mains", "USB",
		"USB_DCP", "USB_CDP", "USB_ACA"
	};

Contention being that laptop-mode-tools should interrogate the 'online'
status for everything but "Battery" to determine ON_AC variable.

Thanks: Todd Broch