It has been a while since dove_defconfig was updated to recent development.
This patch adds all currently available Dove boards, including a DT-enabled
machine.

DT support requires to allow ATAGS passed by boot loader as most of them are
not yet capable of passing DT blobs. Also OF_SERIAL is enabled to actually
see the bootlog.

Finally, sdhci driver for Dove, mv_cesa, GPIO LEDs, and highmem support is
added.
Signed-off-by: Sebastian Hesselbarth <sebastian.hesselbarth@gmail.com>
Signed-off-by: Jason Cooper <jason@lakedaemon.net>