ARM: ux500: call ux500_setup_id later

ux500_setup_id is currently called from u8500_map_io(), which is
really early, but nothing relies on the ID any more, other than
a printk message that is not really all that important to
have early during boot.

If we move the call to ux500_setup_id() into ux500_soc_device_init(),
that file becomes usuable almost entirely standalone, and we can kill
off the u8500_map_io() callback as it just does the default
debug_ll_io_init() now.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>