powerpc: clean up after powermac build merge

Complete moving arch/ppc64/kernel/mpic.h,
        include/asm-ppc/reg.h, include/asm-ppc64/kdebug.h
	        and include/asm-ppc64/kprobes.h
Add arch/powerpc/platforms/Makefile and use it from
	arch/powerpc/Makefile
Introduce OLDARCH temporarily so we can point back to
	the originating architecture

Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>

arch/powerpc/platforms/Makefile

@@ -0,0 +1,4 @@
+obj-$(CONFIG_PPC_PMAC)	+= powermac/
+obj-$(CONFIG_4xx)	+= 4xx/
+obj-$(CONFIG_83xx)	+= 83xx/
+obj-$(CONFIG_85xx)	+= 85xx/

arch/powerpc/platforms/embedded6xx/Kconfig

@@ -2,14 +2,6 @@ choice
 	prompt "Machine Type"
 	depends on EMBEDDED6xx
 
-config APUS
-	bool "Amiga-APUS"
-	depends on BROKEN
-	help
-	  Select APUS if configuring for a PowerUP Amiga.
-	  More information is available at:
-	  <http://linux-apus.sourceforge.net/>.
-
 config KATANA
 	bool "Artesyn-Katana"
 	help