at91sam926x_lowlevel_init: use struct to pass soc config
this will allow to pass more paraemeter to at91sam926x_lowlevel_init
and drop AT91_BASE_SYS
Signed-off-by: Jean-Christophe PLAGNIOL-VILLARD <plagnioj@jcrosoft.com>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>