m68k: fix recursive dependency in Kconfig

We had a recursive dependency between MMU_MOTOROLA and MMU_SUN3
Fix it by dropping the unused dependencies on MMU_MOTOROLA.

MMU_MOTOROLA is set to y only using select so any dependencies
are anyway ignored.
Signed-off-by: NSam Ravnborg <sam@ravnborg.org>
Acked-by: NGeert Uytterhoeven <geert@linux-m68k.org>
Cc: Roman Zippel <zippel@linux-m68k.org>

arch/m68k/Kconfig

@@ -280,7 +280,6 @@ config M68060
 
 config MMU_MOTOROLA
 	bool
-	depends on MMU && !MMU_SUN3
 
 config MMU_SUN3
 	bool