This patch fixes a problem spotted on Glacier/Canyonlands (and most
likely lots of other board ports), that no serial output was seen
after console initialization in console_init_r(). This is because the
last added console device was used instead of the first added.

This patch fixes this problem by using list_add_tail() instead of
list_add() to register a device. This way the first added console
is used again.

Signed-off-by: Stefan Roese <sr@denx.de>