powerpc: Introduce entry_{32,64}.S, misc_{32,64}.S, systbl.S

The system call table has been consolidated into systbl.S.  We have
separate 32-bit and 64-bit versions of entry.S and misc.S since the
code is mostly sufficiently different to be not worth merging.
There are some common bits that will be extracted in future.

Signed-off-by: Paul Mackerras <paulus@samba.org>
diff --git a/arch/powerpc/Makefile b/arch/powerpc/Makefile
index a4c605f..27649cf 100644
--- a/arch/powerpc/Makefile
+++ b/arch/powerpc/Makefile
@@ -119,10 +119,9 @@
 head-$(CONFIG_44x)		:= arch/powerpc/kernel/head_44x.o
 head-$(CONFIG_FSL_BOOKE)	:= arch/powerpc/kernel/head_fsl_booke.o
 
-ifeq ($(CONFIG_PPC32),y)
 head-$(CONFIG_6xx)		+= arch/powerpc/kernel/idle_6xx.o
+head-$(CONFIG_PPC64)		+= arch/powerpc/kernel/entry_64.o
 head-$(CONFIG_PPC_FPU)		+= arch/powerpc/kernel/fpu.o
-endif
 
 core-y				+= arch/powerpc/kernel/ \
 				   arch/$(OLDARCH)/kernel/ \