Disintegrate asm/system.h for Blackfin [ver #2]

Disintegrate asm/system.h for Blackfin.

Signed-off-by: David Howells <dhowells@redhat.com>
cc: uclinux-dist-devel@blackfin.uclinux.org
Signed-off-by: Bob Liu <lliubbo@gmail.com>
diff --git a/arch/blackfin/include/asm/exec.h b/arch/blackfin/include/asm/exec.h
new file mode 100644
index 0000000..54c2e1d
--- /dev/null
+++ b/arch/blackfin/include/asm/exec.h
@@ -0,0 +1 @@
+/* define arch_align_stack() here */