microblaze: uaccess: Unify __copy_tofrom_user

Move to generic location.

Signed-off-by: Michal Simek <monstr@monstr.eu>

arch/microblaze/lib/Makefile

@@ -10,4 +10,4 @@ else
 lib-y += memcpy.o memmove.o
 endif
 
-lib-$(CONFIG_MMU) += uaccess_old.o
+lib-y += uaccess_old.o