at91: fix map_io init usage

switch early init to init_early and introduce soc map_io

with this Patch we will not do any more early device setup during the map io

tks to Russell to point the new call back

Signed-off-by: Jean-Christophe PLAGNIOL-VILLARD <plagnioj@jcrosoft.com>
Cc: Nicolas Ferre <nicolas.ferre@atmel.com>
Cc: Patrice Vilchez <patrice.vilchez@atmel.com>
Acked-by: Russell King <rmk+kernel@arm.linux.org.uk>
Acked-by: Andrew Victor <linux@maxim.org.za>