powerpc: Drop probecpu() in favour of arch_cpu_init()

[u-boot] / board / bf533-ezkit / MAINTAINERS

BF533-EZKIT BOARD
M:      Sonic Zhang <sonic.adi@gmail.com>
S:      Maintained
F:      board/bf533-ezkit/
F:      include/configs/bf533-ezkit.h
F:      configs/bf533-ezkit_defconfig