Blackfin: add check for anomaly 05000362

DESCRIPTION:
The column address width settings for banks 2 and 3 are misconnected in
the SDRAM controller.  Accesses to bank 2 will result in an error if the
Column Address Width for bank 3 (EB3CAW ) is not set to be the same as
that of bank 2.

WORKAROUND:
If using bank 2, make sure that banks 2 and 3 have the same column address
width settings in the EBIU_SDBCTL register.  This must be the case
regardless of whether or not bank 3 is enabled.

Signed-off-by: Mike Frysinger <vapier@gentoo.org>