ARM: configs: Update mvebu defconfig for thermal

The thermal management driver for Armada XP/370 has been added
so we update the defconfig to reflect this.

Signed-off-by: Ezequiel Garcia <ezequiel.garcia@free-electrons.com>
Acked-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: Jason Cooper <jason@lakedaemon.net>