m68k: switch to generic sigaltstack

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
diff --git a/arch/m68k/Kconfig b/arch/m68k/Kconfig
index 6710084..3e73dca7 100644
--- a/arch/m68k/Kconfig
+++ b/arch/m68k/Kconfig
@@ -18,6 +18,7 @@
 	select HAVE_MOD_ARCH_SPECIFIC
 	select MODULES_USE_ELF_REL
 	select MODULES_USE_ELF_RELA
+	select GENERIC_SIGALTSTACK
 
 config RWSEM_GENERIC_SPINLOCK
 	bool