common: Move pci_target_init() to PPC header

Only one boards needs this definition. Move it to an arch-specific header.

Signed-off-by: Simon Glass <sjg@chromium.org>
diff --git a/arch/powerpc/include/asm/4xx_pci.h b/arch/powerpc/include/asm/4xx_pci.h
index f686e7c..a68c875 100644
--- a/arch/powerpc/include/asm/4xx_pci.h
+++ b/arch/powerpc/include/asm/4xx_pci.h
@@ -56,5 +56,6 @@
 int __pci_pre_init(struct pci_controller *hose);
 void __pci_target_init(struct pci_controller *hose);
 void __pci_master_init(struct pci_controller *hose);
+void pci_target_init(struct pci_controller *);
 
 #endif