parisc: switch to generic fork/vfork/clone

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
diff --git a/arch/parisc/Kconfig b/arch/parisc/Kconfig
index 0aec70c..e688a2b 100644
--- a/arch/parisc/Kconfig
+++ b/arch/parisc/Kconfig
@@ -24,6 +24,7 @@
 	select MODULES_USE_ELF_RELA
 	select GENERIC_KERNEL_THREAD
 	select GENERIC_KERNEL_EXECVE
+	select CLONE_BACKWARDS
 
 	help
 	  The PA-RISC microprocessor is designed by Hewlett-Packard and used