of: Merge of_device_alloc() and of_device_make_bus_id()

This patch merges the common routines of_device_alloc() and
of_device_make_bus_id() from powerpc and microblaze.

Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
CC: Michal Simek <monstr@monstr.eu>
CC: Grant Likely <grant.likely@secretlab.ca>
CC: Benjamin Herrenschmidt <benh@kernel.crashing.org>
CC: Stephen Rothwell <sfr@canb.auug.org.au>
CC: microblaze-uclinux@itee.uq.edu.au
CC: linuxppc-dev@ozlabs.org
CC: devicetree-discuss@lists.ozlabs.org
diff --git a/arch/powerpc/kernel/Makefile b/arch/powerpc/kernel/Makefile
index 58d0572..83aa1fd 100644
--- a/arch/powerpc/kernel/Makefile
+++ b/arch/powerpc/kernel/Makefile
@@ -40,7 +40,7 @@
 obj-$(CONFIG_PPC64)		+= vdso64/
 obj-$(CONFIG_ALTIVEC)		+= vecemu.o
 obj-$(CONFIG_PPC_970_NAP)	+= idle_power4.o
-obj-$(CONFIG_PPC_OF)		+= of_device.o of_platform.o prom_parse.o
+obj-$(CONFIG_PPC_OF)		+= of_platform.o prom_parse.o
 obj-$(CONFIG_PPC_CLOCK)		+= clock.o
 procfs-y			:= proc_powerpc.o
 obj-$(CONFIG_PROC_FS)		+= $(procfs-y)