arm: mvebu: Setup the MBUS bridge registers

arm: mvebu: Setup the MBUS bridge registers

With this patch, the MBUS bridge registers (base and size) are
configured upon each call to mbus_dt_setup_win(). This is needed, since
the board code can also call this function in later boot stages. As
done in the maxbcm board.

This is needed to fix a problem with the secondary CPU's not booting
in Linux on AXP.

Signed-off-by: Stefan Roese <sr@denx.de>
Cc: Peter Morrow <peter@senient.com>
Cc: Luka Perkov <luka.perkov@sartura.hr>