ARM: Kirkwood: sort board entries by ASCII-code order

This patch sorts board entries in files Kconfig, Makefile and
kirkwood_defconfig by ASCII-code order.

Signed-off-by: Simon Guinot <simon.guinot@sequanux.org>
Acked-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: Jason Cooper <jason@lakedaemon.net>