score: switch to generic fork/vfork/clone

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
diff --git a/arch/score/Kconfig b/arch/score/Kconfig
index a285e78..4589339 100644
--- a/arch/score/Kconfig
+++ b/arch/score/Kconfig
@@ -15,6 +15,7 @@
 	select MODULES_USE_ELF_REL
 	select GENERIC_KERNEL_THREAD
 	select GENERIC_KERNEL_EXECVE
+	select CLONE_BACKWARDS
 
 choice
 	prompt "System type"