m68k: let Makefile sort out compiling mmu and non-mmu lib/checksum.c

We don't need an arch/m68k/lib/checksum.c wrapper to include the correct
mmu or non-mmu version of the checksum code. Let the Makefile just build
the appropriate one.
Signed-off-by: Greg Ungerer <gerg@uclinux.org>

arch/m68k/lib/Makefile

@@ -4,11 +4,11 @@
 #
 
 lib-y	:= ashldi3.o ashrdi3.o lshrdi3.o muldi3.o \
-	   memcpy.o memset.o memmove.o checksum.o
+	   memcpy.o memset.o memmove.o
 
 ifdef CONFIG_MMU
-lib-y	+= string.o uaccess.o
+lib-y	+= string.o uaccess.o checksum_mm.o
 else
-lib-y	+= mulsi3.o divsi3.o udivsi3.o modsi3.o umodsi3.o delay.o
+lib-y	+= mulsi3.o divsi3.o udivsi3.o modsi3.o umodsi3.o delay.o checksum_no.o
 endif
 

arch/m68k/lib/checksum.c

-#ifdef CONFIG_MMU
-#include "checksum_mm.c"
-#else
-#include "checksum_no.c"
-#endif