[MIPS] Introduce pcibios_plat_setup

Introduce pcibios_plat_setup for platform-specific pcibios_setup.

Signed-off-by: Atsushi Nemoto <anemo@mba.ocn.ne.jp>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
diff --git a/include/asm-mips/pci.h b/include/asm-mips/pci.h
index c205875..5510c53 100644
--- a/include/asm-mips/pci.h
+++ b/include/asm-mips/pci.h
@@ -174,4 +174,6 @@
 
 extern int pci_probe_only;
 
+extern char * (*pcibios_plat_setup)(char *str);
+
 #endif /* _ASM_PCI_H */