powerpc: re-add bi_ip_addr to bd_t struct

powerpc: re-add bi_ip_addr to bd_t struct

Since commit 50a47d0523e8efebe912bef539a77ffd42116451
(net: punt bd->bi_ip_addr) booting old 2.4.x ppc kernels
is broken due to changed offsets of the fields in struct bd_t.
Offsets of the fields after removed bi_ip_addr are wrong,
causing wrong bus clocks and console baudrate configurations
and various other issues. Re-add the bi_ip_addr field to preserve
backward compatibility with older ppc kernels. Setting bi_ip_addr
in board.c is not really needed, grepping in the 2.4 linux tree
shows that bi_ip_addr is not accessed there. Adding bi_ip_addr
to struct bd_t for other arches isn't needed it seems. bd_t is
not used by other arches in the 2.4 linux tree.

Signed-off-by: Anatolij Gustschin <agust@denx.de>
Acked-by: Wolfgang Denk <wd@denx.de>