microblaze: switch to generic fork/vfork/clone

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Michal Simek <michal.simek@xilinx.com>
diff --git a/arch/microblaze/Kconfig b/arch/microblaze/Kconfig
index 198abf6..4bcf891 100644
--- a/arch/microblaze/Kconfig
+++ b/arch/microblaze/Kconfig
@@ -28,6 +28,7 @@
 	select MODULES_USE_ELF_RELA
 	select GENERIC_KERNEL_THREAD
 	select GENERIC_KERNEL_EXECVE
+	select CLONE_BACKWARDS
 
 config SWAP
 	def_bool n