Blackfin: add new cacheflush syscall

Flushing caches sometimes requires anomaly workarounds which require
supervisor-only insns.  Normally we don't need to flush caches from
userspace so this isn't a problem, but when gcc generates trampolines
on the stack, we do.

So add a new syscall for gcc to use modeled after the mips version.

Signed-off-by: Sonic Zhang <sonic.zhang@analog.com>
Signed-off-by: Mike Frysinger <vapier@gentoo.org>
diff --git a/arch/blackfin/include/asm/unistd.h b/arch/blackfin/include/asm/unistd.h
index 14fcd25..928ae97 100644
--- a/arch/blackfin/include/asm/unistd.h
+++ b/arch/blackfin/include/asm/unistd.h
@@ -392,8 +392,9 @@
 #define __NR_fanotify_init	371
 #define __NR_fanotify_mark	372
 #define __NR_prlimit64		373
+#define __NR_cacheflush		374
 
-#define __NR_syscall		374
+#define __NR_syscall		375
 #define NR_syscalls		__NR_syscall
 
 /* Old optional stuff no one actually uses */