powerpc/pci: Fix MODPOST warning

making a powerpc target with PCI support, shows the
following warning:

  MODPOST vmlinux.o
WARNING: vmlinux.o(.text+0x10430): Section mismatch in reference from the
function pcibios_allocate_bus_resources() to the function .init.text:reparent_resources()

The function pcibios_allocate_bus_resources() references
the function __init reparent_resources().

This is often because pcibios_allocate_bus_resources lacks a __init
annotation or the annotation of reparent_resources is wrong.

This patch fix this warning by removing the __init
annotation before reparent_resources.

Signed-off-by: Heiko Schocher <hs@denx.de>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>