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/kernel/process.c b/arch/blackfin/kernel/process.c
index a80a643..c0f4fe2 100644
--- a/arch/blackfin/kernel/process.c
+++ b/arch/blackfin/kernel/process.c
@@ -19,6 +19,7 @@
 #include <asm/blackfin.h>
 #include <asm/fixed_code.h>
 #include <asm/mem_map.h>
+#include <asm/irq.h>
 
 asmlinkage void ret_from_fork(void);