[MIPS] BCM47xx: Fix build error due to missing PCI functions

This patch defines pcibios_map_irq() and pcibios_plat_dev_init() for
the BCM47xx platform.

It fixes the regression introduced by commit
aab547ce0d1493d400b6468c521a0137cd8c1edf.

Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
diff --git a/arch/mips/pci/Makefile b/arch/mips/pci/Makefile
index 15e01ae..c8c32f4 100644
--- a/arch/mips/pci/Makefile
+++ b/arch/mips/pci/Makefile
@@ -15,6 +15,7 @@
 obj-$(CONFIG_PCI_VR41XX)	+= ops-vr41xx.o pci-vr41xx.o
 obj-$(CONFIG_MARKEINS)		+= ops-emma2rh.o pci-emma2rh.o fixup-emma2rh.o
 obj-$(CONFIG_PCI_TX4927)	+= ops-tx4927.o
+obj-$(CONFIG_BCM47XX)		+= pci-bcm47xx.o
 
 #
 # These are still pretty much in the old state, watch, go blind.