m68k: compile appropriate mm arch files for ColdFire MMU support

Create a config symbol to enable when using a ColdFire MMU. We then
use that to only compile the necessary arch mm files.

Signed-off-by: Greg Ungerer <gerg@uclinux.org>
Acked-by: Geert Uytterhoeven <geert@linux-m68k.org>
Acked-by: Matt Waddel <mwaddel@yahoo.com>
Acked-by: Kurt Mahan <kmahan@xmission.com>

arch/m68k/mm/Makefile

@@ -4,6 +4,8 @@
 
 obj-y	:= init.o
 
-obj-$(CONFIG_MMU)		+= cache.o fault.o hwtest.o
-obj-$(CONFIG_MMU_MOTOROLA)	+= kmap.o memory.o motorola.o
-obj-$(CONFIG_MMU_SUN3)		+= sun3kmap.o sun3mmu.o
+obj-$(CONFIG_MMU)		+= cache.o fault.o
+obj-$(CONFIG_MMU_MOTOROLA)	+= kmap.o memory.o motorola.o hwtest.o
+obj-$(CONFIG_MMU_SUN3)		+= sun3kmap.o sun3mmu.o hwtest.o
+obj-$(CONFIG_MMU_COLDFIRE)	+= kmap.o memory.o mcfmmu.o
+