powerpc/83xx: remove staticness for qe_iop_conf_tab

commit a5510058 powerpc/83xx/km: make local functions and structs static

removed the staticness also from this struct. But this struct is needed
in arch/powerpc/cpu/mpc83xx/cpu_init.c and declared as extern.

Signed-off-by: Holger Brunck <holger.brunck@keymile.com>