m68k: make multi_defconfig the default defconfig

It seems to match the intention behind multi_defconfig to make it the
default defconfig.
Signed-off-by: NAdrian Bunk <bunk@kernel.org>
Signed-off-by: NGeert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

arch/m68k/Makefile

@@ -13,7 +13,7 @@
 # Copyright (C) 1994 by Hamish Macdonald
 #
 
-KBUILD_DEFCONFIG := amiga_defconfig
+KBUILD_DEFCONFIG := multi_defconfig
 
 # override top level makefile
 AS += -m68020